date-time-tools
Date Format Converter
Convert common date formats by choosing the source format first, then output ISO, MM/DD/YYYY, DD/MM/YYYY, YYYYMMDD, long date, and Unix seconds reference.
Tool workspace
The interactive tool requires JavaScript.
Instructions
Choose the source format. Slash dates that are not year-first should be explicitly marked as MM/DD/YYYY or DD/MM/YYYY.
Copy the target format you need, then review it before imports, publishing workflows, or formal deadline use.
Use this browser-local converter to clean spreadsheet dates, normalize import fields, check API date parameters, and prepare cross-team handoff text. It converts Gregorian calendar dates only and does not guess ambiguous locale formats.
Direct answer
Date format conversion should start by confirming the source format. Auto-detect only accepts unambiguous year-first values; MM/DD/YYYY and DD/MM/YYYY must be selected explicitly so 01/02/2026 is not silently interpreted the wrong way.
How to use this tool
- Enter a Gregorian date such as 2026-07-11, 2026/7/11, 2026.07.11, 20260711, 07/11/2026, or 11/07/2026.
- Choose the source format. Slash dates that are not year-first should be explicitly marked as MM/DD/YYYY or DD/MM/YYYY.
- Copy the target format you need, then review it before imports, publishing workflows, or formal deadline use.
Why the source format matters
Different regions can read 01/02/2026 as January 2 or February 1. This tool does not promise a locale meaning for ambiguous input; you choose the source format first.
Output formats included
The result includes YYYY-MM-DD, YYYY-MM-DDT00:00:00.000Z, MM/DD/YYYY, DD/MM/YYYY, YYYYMMDD, a long English date, and a Unix seconds reference for spreadsheet, API, filename, and documentation drafts.
Conversion limits
The converter handles dates, not exact time-zone moments, daylight saving time, holidays, make-up workdays, lunar dates, or legal deadline rules. Use the time-zone converter for cross-zone moments and review the source rules.
Frequently asked questions
Why does auto-detect reject 01/02/2026?
Because it may mean January 2 or February 1. Ambiguous slash dates must use an explicit source format.
What is the difference between ISO date and ISO date-time?
YYYY-MM-DD is a calendar date. YYYY-MM-DDT00:00:00.000Z is a UTC-midnight date-time reference. Confirm the expected timezone before treating a date as a moment.
Can I use this for contract or filing deadlines?
Use it only as a formatting helper. Formal deadlines may depend on regional calendars, rollover rules, and institutional interpretation.
Does the tool upload my date?
No. Conversion runs locally in the browser without accounts, databases, backend services, or external APIs.
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