Dates & Scheduling

Cron Next-Run Calculator

Type a cron expression, pick a time zone, and see exactly when it will next run. Everything is calculated in your browser — nothing is uploaded.

Runs in your browser v1.0.0

Cron schedule

5 fields

Cron expression

Fields: minute hour day-of-month month day-of-week. Supports *, ranges (9-17), steps (*/15), lists (1,15) and names (JAN, MON).

Time zone

Runs to show

Advanced: calculate from a specific time

First run after

Upcoming runs

local time

How it works

The expression is expanded into matching minutes, then each run is resolved against the browser’s native Intl time zone rules. Daylight saving transitions are handled automatically, so times that do not exist on a spring-forward day are skipped and offsets are shown for each run. Your schedule never leaves the page.

Practical uses

Expand a standard five-field cron expression and list the next execution times in a chosen IANA time zone.

Common ways to use it

Confirm when a cron job will next fire for a colleague in another time zone.
Check a schedule around a daylight-saving transition.
Export the upcoming run times as a CSV.

Business hours every 15 minutes in UTC

Input

Cron: */15 9-17 * * 1-5
Time zone: UTC
First run after: 2026-01-01T00:00:00Z
Runs to show: 6

Output

2026-01-01T09:00:00.000Z
2026-01-01T09:15:00.000Z
2026-01-01T09:30:00.000Z
2026-01-01T09:45:00.000Z
2026-01-01T10:00:00.000Z
2026-01-01T10:15:00.000Z

Verified with the tool's nextRuns function; runs are strictly after the reference instant. Field order is minute hour day-of-month month day-of-week. Resolved in America/New_York from 2026-09-14T12:00:00Z, the same expression starts at 2026-09-14T13:00:00.000Z, shown as "Mon, 14 Sep 2026 09:00 (UTC-04:00)".

Options that matter

Cron expression — five fields supporting *, ranges (9-17), steps (*/15), lists (1,15) and names (JAN, MON), plus macros such as @daily.
Time zone — any IANA zone; each run is resolved with the browser Intl rules and shown with its UTC offset for that date.
Runs to show — 5, 10, 20 or 50.
First run after — an optional datetime-local reference instead of the current time.

Things to keep in mind

Standard five-field cron only; a six-field (seconds) expression is rejected.
Results depend on the IANA time-zone data available to the browser's Intl implementation.
A wall-clock time skipped by a daylight-saving spring-forward is omitted rather than shifted, so some days can have fewer runs.
The @reboot macro is recognised but has no calculable schedule, and impossible dates such as 30 February return no runs; the search window is about eight years.