JavaScript & Browser
JavaScript Date Tester
Paste any value you would pass to new Date() and see exactly how JavaScript
parses and formats it — including the UTC-versus-local time zone gotchas that trip
people up. Everything runs in your browser.
Value passed to new Date()
Local time
Try an ISO date (2024-01-01), a local date-time
(2024-01-01T09:30), a UTC instant (2024-01-01T09:30:00Z),
or an offset (2024-01-01T09:30:00+05:30).
Parse result
——
How it was parsed
Components
—Formatted output
liveHow it works
Your value is passed to the browser’s own new Date(), so you are testing
the exact engine your users run. Date-only ISO strings such as 2024-01-01 are
parsed as UTC midnight, while date-times without a Z or offset are parsed as
local time — switching the display time zone shows how that shifts the calendar date.
Formatting uses the native toISOString, toLocale* and
Intl.DateTimeFormat APIs. Nothing is uploaded and no external service is called.