fix: comments resolved moved to signoz btn added testcase for querydelete

frontend/src/components/CustomTimePicker/CustomTimePicker.styles.scss

@@ -1,6 +1,31 @@
 .custom-time-picker {
 	display: flex;
-	flex-direction: column;
+	flex-direction: row;
+	align-items: center;
+	gap: 4px;
+
+	.zoom-out-btn {
+		display: flex;
+		align-items: center;
+		justify-content: center;
+		flex-shrink: 0;
+		color: var(--foreground);
+		border: 1px solid var(--border);
+		border-radius: 2px;
+		box-shadow: none;
+		padding: 10px;
+		height: 33px;
+
+		&:hover:not(:disabled) {
+			color: var(--bg-vanilla-100);
+			background: var(--primary);
+		}
+
+		&:disabled {
+			opacity: 0.5;
+			cursor: not-allowed;
+		}
+	}
 
 	.timeSelection-input {
 		&:hover {

frontend/src/components/CustomTimePicker/CustomTimePicker.tsx

@@ -7,9 +7,11 @@ import {
 	useState,
 } from 'react';
 import { useLocation } from 'react-router-dom';
+import { Button } from '@signozhq/button';
 import { Input, InputRef, Popover, Tooltip } from 'antd';
 import cx from 'classnames';
 import { DATE_TIME_FORMATS } from 'constants/dateTimeFormats';
+import { QueryParams } from 'constants/query';
 import { DateTimeRangeType } from 'container/TopNav/CustomDateTimeModal';
 import {
 	FixedDurationSuggestionOptions,
@@ -17,9 +19,11 @@ import {
 	RelativeDurationSuggestionOptions,
 } from 'container/TopNav/DateTimeSelectionV2/constants';
 import dayjs from 'dayjs';
+import { useZoomOut } from 'hooks/useZoomOut';
 import { isValidShortHandDateTimeFormat } from 'lib/getMinMax';
+import { isZoomOutDisabled } from 'lib/zoomOutUtils';
 import { defaultTo, isFunction, noop } from 'lodash-es';
-import { ChevronDown, ChevronUp } from 'lucide-react';
+import { ChevronDown, ChevronUp, ZoomOut } from 'lucide-react';
 import { useTimezone } from 'providers/Timezone';
 import { getTimeDifference, validateEpochRange } from 'utils/epochUtils';
 import { popupContainer } from 'utils/selectPopupContainer';
@@ -112,6 +116,14 @@ function CustomTimePicker({
 
 	const [isOpenedFromFooter, setIsOpenedFromFooter] = useState(false);
 
+	const durationMs = (maxTime - minTime) / 1e6;
+	const zoomOutDisabled = showLiveLogs || isZoomOutDisabled(durationMs);
+
+	const handleZoomOut = useZoomOut({
+		isDisabled: zoomOutDisabled,
+		urlParamsToDelete: [QueryParams.activeLogId],
+	});
+
 	// function to get selected time in Last 1m, Last 2h, Last 3d, Last 4w format
 	// 1m, 2h, 3d, 4w -> Last 1 minute, Last 2 hours, Last 3 days, Last 4 weeks
 	const getSelectedTimeRangeLabelInRelativeFormat = (
@@ -585,6 +597,24 @@ function CustomTimePicker({
 					/>
 				</Popover>
 			</Tooltip>
+			{!showLiveLogs && (
+				<Tooltip
+					title={
+						zoomOutDisabled ? 'Zoom out time range is limited to 1 month' : 'Zoom out'
+					}
+				>
+					<span>
+						<Button
+							className="zoom-out-btn"
+							onClick={handleZoomOut}
+							disabled={zoomOutDisabled}
+							data-testid="zoom-out-btn"
+						>
+							<ZoomOut size={14} />
+						</Button>
+					</span>
+				</Tooltip>
+			)}
 		</div>
 	);
 }

frontend/src/components/CustomTimePicker/__tests__/customTimePickerZoomOut.test.tsx

@@ -0,0 +1,157 @@
+import { render, screen } from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
+import { QueryParams } from 'constants/query';
+import { GlobalReducer } from 'types/reducer/globalTime';
+
+import CustomTimePicker from '../CustomTimePicker';
+
+const MS_PER_MIN = 60 * 1000;
+const NOW_MS = 1705312800000;
+
+const mockDispatch = jest.fn();
+const mockSafeNavigate = jest.fn();
+const mockUrlQueryDelete = jest.fn();
+const mockUrlQuerySet = jest.fn();
+
+interface MockAppState {
+	globalTime: Pick<GlobalReducer, 'minTime' | 'maxTime'>;
+}
+
+jest.mock('react-redux', () => ({
+	useDispatch: (): jest.Mock => mockDispatch,
+	useSelector: (selector: (state: MockAppState) => unknown): unknown => {
+		const mockState: MockAppState = {
+			globalTime: {
+				minTime: (NOW_MS - 15 * MS_PER_MIN) * 1e6,
+				maxTime: NOW_MS * 1e6,
+			},
+		};
+		return selector(mockState);
+	},
+}));
+
+jest.mock('hooks/useSafeNavigate', () => ({
+	useSafeNavigate: (): { safeNavigate: jest.Mock } => ({
+		safeNavigate: mockSafeNavigate,
+	}),
+}));
+
+interface MockUrlQuery {
+	delete: typeof mockUrlQueryDelete;
+	set: typeof mockUrlQuerySet;
+	get: () => null;
+	toString: () => string;
+}
+
+jest.mock('hooks/useUrlQuery', () => ({
+	__esModule: true,
+	default: (): MockUrlQuery => ({
+		delete: mockUrlQueryDelete,
+		set: mockUrlQuerySet,
+		get: (): null => null,
+		toString: (): string => 'relativeTime=45m',
+	}),
+}));
+
+jest.mock('providers/Timezone', () => ({
+	useTimezone: (): { timezone: { value: string; offset: string } } => ({
+		timezone: { value: 'UTC', offset: 'UTC' },
+	}),
+}));
+
+jest.mock('react-router-dom', () => ({
+	useLocation: (): { pathname: string } => ({ pathname: '/logs-explorer' }),
+}));
+
+const MS_PER_DAY = 24 * 60 * 60 * 1000;
+const now = Date.now();
+const defaultProps = {
+	onSelect: jest.fn(),
+	onError: jest.fn(),
+	selectedValue: '15m',
+	selectedTime: '15m',
+	onValidCustomDateChange: jest.fn(),
+	open: false,
+	setOpen: jest.fn(),
+	items: [
+		{ value: '15m', label: 'Last 15 minutes' },
+		{ value: '1h', label: 'Last 1 hour' },
+	],
+	minTime: (now - 15 * 60 * 1000) * 1e6,
+	maxTime: now * 1e6,
+};
+
+describe('CustomTimePicker - zoom out button', () => {
+	beforeEach(() => {
+		jest.clearAllMocks();
+		jest.spyOn(Date, 'now').mockReturnValue(NOW_MS);
+	});
+
+	afterEach(() => {
+		jest.restoreAllMocks();
+	});
+
+	it('should render zoom out button when showLiveLogs is false', () => {
+		render(<CustomTimePicker {...defaultProps} showLiveLogs={false} />);
+
+		expect(screen.getByTestId('zoom-out-btn')).toBeInTheDocument();
+	});
+
+	it('should not render zoom out button when showLiveLogs is true', () => {
+		render(<CustomTimePicker {...defaultProps} showLiveLogs={true} />);
+
+		expect(screen.queryByTestId('zoom-out-btn')).not.toBeInTheDocument();
+	});
+
+	it('should call handleZoomOut when zoom out button is clicked', async () => {
+		render(<CustomTimePicker {...defaultProps} showLiveLogs={false} />);
+
+		const zoomOutBtn = screen.getByTestId('zoom-out-btn');
+		await userEvent.click(zoomOutBtn);
+
+		expect(mockDispatch).toHaveBeenCalled();
+		expect(mockUrlQuerySet).toHaveBeenCalledWith(QueryParams.relativeTime, '45m');
+		expect(mockSafeNavigate).toHaveBeenCalledWith(
+			expect.stringMatching(/\/logs-explorer\?relativeTime=45m/),
+		);
+	});
+
+	it('should use real ladder logic: 15m range zooms to 45m preset and updates URL', async () => {
+		render(<CustomTimePicker {...defaultProps} showLiveLogs={false} />);
+
+		const zoomOutBtn = screen.getByTestId('zoom-out-btn');
+		await userEvent.click(zoomOutBtn);
+
+		expect(mockUrlQueryDelete).toHaveBeenCalledWith(QueryParams.startTime);
+		expect(mockUrlQueryDelete).toHaveBeenCalledWith(QueryParams.endTime);
+		expect(mockUrlQuerySet).toHaveBeenCalledWith(QueryParams.relativeTime, '45m');
+		expect(mockSafeNavigate).toHaveBeenCalledWith(
+			expect.stringMatching(/\/logs-explorer\?relativeTime=45m/),
+		);
+		expect(mockDispatch).toHaveBeenCalled();
+	});
+
+	it('should delete activeLogId when zoom out is clicked', async () => {
+		render(<CustomTimePicker {...defaultProps} showLiveLogs={false} />);
+
+		const zoomOutBtn = screen.getByTestId('zoom-out-btn');
+		await userEvent.click(zoomOutBtn);
+
+		expect(mockUrlQueryDelete).toHaveBeenCalledWith(QueryParams.activeLogId);
+	});
+
+	it('should disable zoom button when time range is >= 1 month', () => {
+		const now = Date.now();
+		render(
+			<CustomTimePicker
+				{...defaultProps}
+				minTime={(now - 31 * MS_PER_DAY) * 1e6}
+				maxTime={now * 1e6}
+				showLiveLogs={false}
+			/>,
+		);
+
+		const zoomOutBtn = screen.getByTestId('zoom-out-btn');
+		expect(zoomOutBtn).toBeDisabled();
+	});
+});

frontend/src/hooks/__tests__/useZoomOut.test.ts

@@ -0,0 +1,160 @@
+import { act, renderHook } from '@testing-library/react';
+import { QueryParams } from 'constants/query';
+import { GlobalReducer } from 'types/reducer/globalTime';
+
+import { useZoomOut } from '../useZoomOut';
+
+const mockDispatch = jest.fn();
+const mockSafeNavigate = jest.fn();
+const mockUrlQueryDelete = jest.fn();
+const mockUrlQuerySet = jest.fn();
+const mockUrlQueryToString = jest.fn(() => '');
+
+interface MockAppState {
+	globalTime: Pick<GlobalReducer, 'minTime' | 'maxTime'>;
+}
+
+jest.mock('react-redux', () => ({
+	useDispatch: (): jest.Mock => mockDispatch,
+	useSelector: <T>(selector: (state: MockAppState) => T): T => {
+		const mockState: MockAppState = {
+			globalTime: {
+				minTime: 15 * 60 * 1000 * 1e6, // 15 min in nanoseconds
+				maxTime: 30 * 60 * 1000 * 1e6, // 30 min in nanoseconds (mock for getNextZoomOutRange)
+			},
+		};
+		return selector(mockState);
+	},
+}));
+
+jest.mock('react-router-dom', () => ({
+	useLocation: (): { pathname: string } => ({ pathname: '/logs-explorer' }),
+}));
+
+jest.mock('hooks/useSafeNavigate', () => ({
+	useSafeNavigate: (): { safeNavigate: typeof mockSafeNavigate } => ({
+		safeNavigate: mockSafeNavigate,
+	}),
+}));
+
+interface MockUrlQuery {
+	delete: typeof mockUrlQueryDelete;
+	set: typeof mockUrlQuerySet;
+	get: () => null;
+	toString: typeof mockUrlQueryToString;
+}
+
+jest.mock('hooks/useUrlQuery', () => ({
+	__esModule: true,
+	default: (): MockUrlQuery => ({
+		delete: mockUrlQueryDelete,
+		set: mockUrlQuerySet,
+		get: (): null => null,
+		toString: mockUrlQueryToString,
+	}),
+}));
+
+const mockGetNextZoomOutRange = jest.fn();
+jest.mock('lib/zoomOutUtils', () => ({
+	getNextZoomOutRange: (
+		...args: unknown[]
+	): ReturnType<typeof mockGetNextZoomOutRange> =>
+		mockGetNextZoomOutRange(...args),
+}));
+
+describe('useZoomOut', () => {
+	beforeEach(() => {
+		jest.clearAllMocks();
+		mockUrlQueryToString.mockReturnValue('relativeTime=45m');
+	});
+
+	it('should do nothing when isDisabled is true', () => {
+		const { result } = renderHook(() => useZoomOut({ isDisabled: true }));
+
+		act(() => {
+			result.current();
+		});
+
+		expect(mockGetNextZoomOutRange).not.toHaveBeenCalled();
+		expect(mockDispatch).not.toHaveBeenCalled();
+		expect(mockSafeNavigate).not.toHaveBeenCalled();
+	});
+
+	it('should do nothing when getNextZoomOutRange returns null', () => {
+		mockGetNextZoomOutRange.mockReturnValue(null);
+
+		const { result } = renderHook(() => useZoomOut());
+
+		act(() => {
+			result.current();
+		});
+
+		expect(mockGetNextZoomOutRange).toHaveBeenCalled();
+		expect(mockDispatch).not.toHaveBeenCalled();
+		expect(mockSafeNavigate).not.toHaveBeenCalled();
+	});
+
+	it('should dispatch preset and update URL when result has preset', () => {
+		mockGetNextZoomOutRange.mockReturnValue({
+			range: [1000, 2000],
+			preset: '45m',
+		});
+
+		const { result } = renderHook(() => useZoomOut());
+
+		act(() => {
+			result.current();
+		});
+
+		expect(mockDispatch).toHaveBeenCalledWith(expect.any(Function));
+		expect(mockUrlQueryDelete).toHaveBeenCalledWith(QueryParams.startTime);
+		expect(mockUrlQueryDelete).toHaveBeenCalledWith(QueryParams.endTime);
+		expect(mockUrlQuerySet).toHaveBeenCalledWith(QueryParams.relativeTime, '45m');
+		expect(mockSafeNavigate).toHaveBeenCalledWith(
+			expect.stringContaining('/logs-explorer'),
+		);
+	});
+
+	it('should dispatch custom range and update URL when result has no preset', () => {
+		mockGetNextZoomOutRange.mockReturnValue({
+			range: [1000000, 2000000],
+			preset: null,
+		});
+
+		const { result } = renderHook(() => useZoomOut());
+
+		act(() => {
+			result.current();
+		});
+
+		expect(mockDispatch).toHaveBeenCalledWith(expect.any(Function));
+		expect(mockUrlQuerySet).toHaveBeenCalledWith(
+			QueryParams.startTime,
+			'1000000',
+		);
+		expect(mockUrlQuerySet).toHaveBeenCalledWith(QueryParams.endTime, '2000000');
+		expect(mockUrlQueryDelete).toHaveBeenCalledWith(QueryParams.relativeTime);
+		expect(mockSafeNavigate).toHaveBeenCalledWith(
+			expect.stringContaining('/logs-explorer'),
+		);
+	});
+
+	it('should delete urlParamsToDelete when provided', () => {
+		mockGetNextZoomOutRange.mockReturnValue({
+			range: [1000, 2000],
+			preset: '45m',
+		});
+
+		const { result } = renderHook(() =>
+			useZoomOut({
+				urlParamsToDelete: [QueryParams.activeLogId],
+			}),
+		);
+
+		act(() => {
+			result.current();
+		});
+
+		expect(mockUrlQueryDelete).toHaveBeenCalledWith(QueryParams.activeLogId);
+	});
+});

frontend/src/hooks/useZoomOut.ts

@@ -0,0 +1,74 @@
+import { useCallback } from 'react';
+// eslint-disable-next-line no-restricted-imports
+import { useDispatch, useSelector } from 'react-redux';
+import { useLocation } from 'react-router-dom';
+import { QueryParams } from 'constants/query';
+import { useSafeNavigate } from 'hooks/useSafeNavigate';
+import useUrlQuery from 'hooks/useUrlQuery';
+import { getNextZoomOutRange } from 'lib/zoomOutUtils';
+import { UpdateTimeInterval } from 'store/actions';
+import { AppState } from 'store/reducers';
+import { GlobalReducer } from 'types/reducer/globalTime';
+
+export interface UseZoomOutOptions {
+	/** When true, the zoom out handler does nothing (e.g. when live logs are enabled) */
+	isDisabled?: boolean;
+	/** URL params to delete when zooming out (e.g. [QueryParams.activeLogId] for logs) */
+	urlParamsToDelete?: string[];
+}
+
+/**
+ * Reusable hook for zoom-out functionality in explorers (logs, traces, etc.).
+ * Computes the next time range using the zoom-out ladder, updates Redux global time,
+ * and navigates with the new URL params.
+ */
+export function useZoomOut(options: UseZoomOutOptions = {}): () => void {
+	const { isDisabled = false, urlParamsToDelete = [] } = options;
+
+	const dispatch = useDispatch();
+	const { minTime, maxTime } = useSelector<AppState, GlobalReducer>(
+		(state) => state.globalTime,
+	);
+	const urlQuery = useUrlQuery();
+	const location = useLocation();
+	const { safeNavigate } = useSafeNavigate();
+
+	return useCallback((): void => {
+		if (isDisabled) {
+			return;
+		}
+		const minMs = Math.floor((minTime ?? 0) / 1e6);
+		const maxMs = Math.floor((maxTime ?? 0) / 1e6);
+		const result = getNextZoomOutRange(minMs, maxMs);
+		if (!result) {
+			return;
+		}
+		const [newStartMs, newEndMs] = result.range;
+		const { preset } = result;
+
+		if (preset) {
+			dispatch(UpdateTimeInterval(preset));
+			urlQuery.delete(QueryParams.startTime);
+			urlQuery.delete(QueryParams.endTime);
+			urlQuery.set(QueryParams.relativeTime, preset);
+		} else {
+			dispatch(UpdateTimeInterval('custom', [newStartMs, newEndMs]));
+			urlQuery.set(QueryParams.startTime, String(newStartMs));
+			urlQuery.set(QueryParams.endTime, String(newEndMs));
+			urlQuery.delete(QueryParams.relativeTime);
+		}
+		for (const param of urlParamsToDelete) {
+			urlQuery.delete(param);
+		}
+		safeNavigate(`${location.pathname}?${urlQuery.toString()}`);
+	}, [
+		dispatch,
+		isDisabled,
+		location.pathname,
+		maxTime,
+		minTime,
+		safeNavigate,
+		urlParamsToDelete,
+		urlQuery,
+	]);
+}

frontend/src/lib/__tests__/zoomOutUtils.test.ts

@@ -0,0 +1,147 @@
+import {
+	getNextDurationInLadder,
+	getNextZoomOutRange,
+	isZoomOutDisabled,
+	ZoomOutResult,
+} from '../zoomOutUtils';
+
+const MS_PER_MIN = 60 * 1000;
+const MS_PER_HOUR = 60 * MS_PER_MIN;
+const MS_PER_DAY = 24 * MS_PER_HOUR;
+const MS_PER_WEEK = 7 * MS_PER_DAY;
+
+// Fixed "now" for deterministic tests: 2024-01-15 12:00:00 UTC
+const NOW_MS = 1705312800000;
+
+describe('zoomOutUtils', () => {
+	beforeEach(() => {
+		jest.spyOn(Date, 'now').mockReturnValue(NOW_MS);
+	});
+
+	afterEach(() => {
+		jest.restoreAllMocks();
+	});
+
+	describe('getNextDurationInLadder', () => {
+		it('should use 3x zoom out below 15m until reaching 15m', () => {
+			expect(getNextDurationInLadder(1 * MS_PER_MIN)).toBe(3 * MS_PER_MIN);
+			expect(getNextDurationInLadder(2 * MS_PER_MIN)).toBe(6 * MS_PER_MIN);
+			expect(getNextDurationInLadder(3 * MS_PER_MIN)).toBe(9 * MS_PER_MIN);
+			expect(getNextDurationInLadder(4 * MS_PER_MIN)).toBe(12 * MS_PER_MIN);
+			expect(getNextDurationInLadder(5 * MS_PER_MIN)).toBe(15 * MS_PER_MIN); // cap at 15m
+			expect(getNextDurationInLadder(6 * MS_PER_MIN)).toBe(15 * MS_PER_MIN); // 18m capped
+		});
+
+		it('should return next step for each ladder rung from 15m onward', () => {
+			expect(getNextDurationInLadder(10 * MS_PER_MIN)).toBe(15 * MS_PER_MIN);
+			expect(getNextDurationInLadder(15 * MS_PER_MIN)).toBe(45 * MS_PER_MIN);
+			expect(getNextDurationInLadder(45 * MS_PER_MIN)).toBe(2 * MS_PER_HOUR);
+			expect(getNextDurationInLadder(2 * MS_PER_HOUR)).toBe(7 * MS_PER_HOUR);
+			expect(getNextDurationInLadder(7 * MS_PER_HOUR)).toBe(21 * MS_PER_HOUR);
+			expect(getNextDurationInLadder(21 * MS_PER_HOUR)).toBe(1 * MS_PER_DAY);
+			expect(getNextDurationInLadder(1 * MS_PER_DAY)).toBe(2 * MS_PER_DAY);
+			expect(getNextDurationInLadder(2 * MS_PER_DAY)).toBe(3 * MS_PER_DAY);
+			expect(getNextDurationInLadder(3 * MS_PER_DAY)).toBe(1 * MS_PER_WEEK);
+			expect(getNextDurationInLadder(1 * MS_PER_WEEK)).toBe(2 * MS_PER_WEEK);
+			expect(getNextDurationInLadder(2 * MS_PER_WEEK)).toBe(30 * MS_PER_DAY);
+		});
+
+		it('should return MAX when at or past 1 month (no wrap)', () => {
+			expect(getNextDurationInLadder(30 * MS_PER_DAY)).toBe(30 * MS_PER_DAY);
+			expect(getNextDurationInLadder(31 * MS_PER_DAY)).toBe(30 * MS_PER_DAY);
+		});
+
+		it('should return next step for duration between ladder rungs', () => {
+			expect(getNextDurationInLadder(1 * MS_PER_HOUR)).toBe(2 * MS_PER_HOUR);
+			expect(getNextDurationInLadder(5 * MS_PER_HOUR)).toBe(7 * MS_PER_HOUR);
+			expect(getNextDurationInLadder(12 * MS_PER_HOUR)).toBe(21 * MS_PER_HOUR);
+		});
+	});
+
+	describe('getNextZoomOutRange', () => {
+		it('should return null when duration is zero or negative', () => {
+			expect(getNextZoomOutRange(NOW_MS, NOW_MS)).toBeNull();
+			expect(getNextZoomOutRange(NOW_MS, NOW_MS - 1000)).toBeNull();
+		});
+
+		it('should return center-anchored range when new end does not exceed now (Phase 1)', () => {
+			// 15m range centered well before now so zoom to 45m keeps end <= now
+			// Center at now-30m: end = center + 22.5m = now - 7.5m <= now
+			const centerMs = NOW_MS - 30 * MS_PER_MIN;
+			const start15m = centerMs - 7.5 * MS_PER_MIN;
+			const end15m = centerMs + 7.5 * MS_PER_MIN;
+			const result = getNextZoomOutRange(start15m, end15m) as ZoomOutResult;
+
+			expect(result).not.toBeNull();
+			expect(result.preset).toBe('45m');
+			const [newStart, newEnd] = result.range;
+			expect(newEnd - newStart).toBe(45 * MS_PER_MIN);
+			const newCenter = (newStart + newEnd) / 2;
+			expect(Math.abs(newCenter - centerMs)).toBeLessThan(2000);
+			expect(newEnd).toBeLessThanOrEqual(NOW_MS + 1000);
+		});
+
+		it('should return end-anchored range when new end would exceed now (Phase 2)', () => {
+			// 22hr range ending at now - zoom to 1d (24hr) would push end past now
+			// Next ladder step from 22hr is 1d
+			const start22h = NOW_MS - 22 * MS_PER_HOUR;
+			const end22h = NOW_MS;
+			const result = getNextZoomOutRange(start22h, end22h) as ZoomOutResult;
+
+			expect(result).not.toBeNull();
+			expect(result.preset).toBe('1d');
+			const [newStart, newEnd] = result.range;
+			expect(newEnd).toBe(NOW_MS); // End anchored at now
+			expect(newStart).toBe(NOW_MS - 1 * MS_PER_DAY);
+		});
+
+		it('should return correct preset for each ladder step', () => {
+			const presets: [number, number, string][] = [
+				[15 * MS_PER_MIN, 0, '45m'],
+				[45 * MS_PER_MIN, 0, '2h'],
+				[2 * MS_PER_HOUR, 0, '7h'],
+				[7 * MS_PER_HOUR, 0, '21h'],
+				[21 * MS_PER_HOUR, 0, '1d'],
+				[1 * MS_PER_DAY, 0, '2d'],
+				[2 * MS_PER_DAY, 0, '3d'],
+				[3 * MS_PER_DAY, 0, '1w'],
+				[1 * MS_PER_WEEK, 0, '2w'],
+				[2 * MS_PER_WEEK, 0, '1month'],
+			];
+
+			presets.forEach(([durationMs, offset, expectedPreset]) => {
+				const end = NOW_MS - offset;
+				const start = end - durationMs;
+				const result = getNextZoomOutRange(start, end);
+				expect(result?.preset).toBe(expectedPreset);
+			});
+		});
+
+		it('isZoomOutDisabled returns true when duration >= 1 month', () => {
+			expect(isZoomOutDisabled(30 * MS_PER_DAY)).toBe(true);
+			expect(isZoomOutDisabled(31 * MS_PER_DAY)).toBe(true);
+			expect(isZoomOutDisabled(29 * MS_PER_DAY)).toBe(false);
+			expect(isZoomOutDisabled(15 * MS_PER_MIN)).toBe(false);
+		});
+
+		it('should return null when at 1 month (no zoom out beyond max)', () => {
+			const start1m = NOW_MS - 30 * MS_PER_DAY;
+			const end1m = NOW_MS;
+			const result = getNextZoomOutRange(start1m, end1m);
+
+			expect(result).toBeNull();
+		});
+
+		it('should zoom out 3x from 5m range to 15m then continue with ladder', () => {
+			// 5m range ending at now → 3x = 15m
+			const start5m = NOW_MS - 5 * MS_PER_MIN;
+			const end5m = NOW_MS;
+			const result = getNextZoomOutRange(start5m, end5m) as ZoomOutResult;
+
+			expect(result).not.toBeNull();
+			expect(result.preset).toBe('15m');
+			const [newStart, newEnd] = result.range;
+			expect(newEnd - newStart).toBe(15 * MS_PER_MIN);
+		});
+	});
+});

frontend/src/lib/zoomOutUtils.ts

@@ -0,0 +1,136 @@
+/**
+ * Custom Time Picker zoom-out ladder:
+ * - Until 1 day: 15m → 45m → 2hr → 7hr → 21hr
+ * - Then fixed: 1d → 2d → 3d → 1w → 2w → 1m
+ * - At 1 month: zoom out is disabled (max range)
+ */
+
+import type {
+	CustomTimeType,
+	Time,
+} from 'container/TopNav/DateTimeSelectionV2/types';
+
+const MS_PER_MIN = 60 * 1000;
+const MS_PER_HOUR = 60 * MS_PER_MIN;
+const MS_PER_DAY = 24 * MS_PER_HOUR;
+const MS_PER_WEEK = 7 * MS_PER_DAY;
+
+const ZOOM_OUT_LADDER_MS: number[] = [
+	15 * MS_PER_MIN, // 15m
+	45 * MS_PER_MIN, // 45m
+	2 * MS_PER_HOUR, // 2hr
+	7 * MS_PER_HOUR, // 7hr
+	21 * MS_PER_HOUR, // 21hr
+	1 * MS_PER_DAY, // 1d
+	2 * MS_PER_DAY, // 2d
+	3 * MS_PER_DAY, // 3d
+	1 * MS_PER_WEEK, // 1w
+	2 * MS_PER_WEEK, // 2w
+	30 * MS_PER_DAY, // 1m
+];
+
+const LADDER_LAST_INDEX = ZOOM_OUT_LADDER_MS.length - 1;
+const MAX_DURATION = ZOOM_OUT_LADDER_MS[LADDER_LAST_INDEX];
+const MIN_LADDER_DURATION_MS = ZOOM_OUT_LADDER_MS[0]; // 15m - below this we use 3x
+
+export const MAX_ZOOM_OUT_DURATION_MS = MAX_DURATION;
+
+/** Returns true when zoom out should be disabled (range at or beyond 1 month) */
+export function isZoomOutDisabled(durationMs: number): boolean {
+	return durationMs >= MAX_ZOOM_OUT_DURATION_MS;
+}
+
+/** Preset labels for ladder steps supported by GetMinMax (shows "Last 15 minutes" etc. instead of "Custom") */
+const PRESET_FOR_DURATION_MS: Record<number, Time | CustomTimeType> = {
+	[15 * MS_PER_MIN]: '15m',
+	[45 * MS_PER_MIN]: '45m',
+	[2 * MS_PER_HOUR]: '2h',
+	[7 * MS_PER_HOUR]: '7h',
+	[21 * MS_PER_HOUR]: '21h',
+	[1 * MS_PER_DAY]: '1d',
+	[2 * MS_PER_DAY]: '2d',
+	[3 * MS_PER_DAY]: '3d',
+	[1 * MS_PER_WEEK]: '1w',
+	[2 * MS_PER_WEEK]: '2w',
+	[30 * MS_PER_DAY]: '1month',
+};
+
+/**
+ * Returns the next duration in the zoom-out ladder for the given current duration.
+ * Below 15m: zoom out 3x until we reach 15m, then continue with the ladder.
+ * If at or past 1 month, returns MAX_DURATION (no zoom out - button is disabled).
+ */
+export function getNextDurationInLadder(durationMs: number): number {
+	if (durationMs >= MAX_DURATION) {
+		return MAX_DURATION; // No zoom out beyond 1 month
+	}
+
+	// Below 15m: zoom out 3x until we reach 15m
+	if (durationMs < MIN_LADDER_DURATION_MS) {
+		const next = durationMs * 3;
+		return Math.min(next, MIN_LADDER_DURATION_MS);
+	}
+
+	// At or above 15m: use the fixed ladder
+	for (let i = 0; i < ZOOM_OUT_LADDER_MS.length; i++) {
+		if (ZOOM_OUT_LADDER_MS[i] > durationMs) {
+			return ZOOM_OUT_LADDER_MS[i];
+		}
+	}
+
+	return MAX_DURATION;
+}
+
+export interface ZoomOutResult {
+	range: [number, number];
+	/** Preset key (e.g. '15m') when range matches a preset - use for display instead of "Custom Date Range" */
+	preset: Time | CustomTimeType | null;
+}
+
+/**
+ * Computes the next zoomed-out time range.
+ * Phase 1 (center-anchored): While new end <= now, expand from center.
+ * Phase 2 (end-anchored at now): When new end would exceed now, anchor end at now and move start backward.
+ *
+ * @returns ZoomOutResult with range and preset (or null if no change)
+ */
+export function getNextZoomOutRange(
+	startMs: number,
+	endMs: number,
+): ZoomOutResult | null {
+	const nowMs = Date.now();
+	const durationMs = endMs - startMs;
+
+	if (durationMs <= 0) {
+		return null;
+	}
+
+	const newDurationMs = getNextDurationInLadder(durationMs);
+
+	// No zoom out when already at max (1 month)
+	if (newDurationMs <= durationMs) {
+		return null;
+	}
+	const centerMs = startMs + durationMs / 2;
+	const computedEndMs = centerMs + newDurationMs / 2;
+
+	let newStartMs: number;
+	let newEndMs: number;
+
+	if (computedEndMs <= nowMs) {
+		// Phase 1: center-anchored
+		newStartMs = centerMs - newDurationMs / 2;
+		newEndMs = computedEndMs;
+	} else {
+		// Phase 2: end-anchored at now
+		newStartMs = nowMs - newDurationMs;
+		newEndMs = nowMs;
+	}
+
+	const preset = PRESET_FOR_DURATION_MS[newDurationMs] ?? null;
+
+	return {
+		range: [Math.round(newStartMs), Math.round(newEndMs)],
+		preset,
+	};
+}