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How to use Date Format Calc

Enter any parseable date string and optionally a custom pattern using tokens like YYYY, MM and DD. A table shows the same date rendered in every supported format.

Frequently asked questions

What custom tokens are supported?

YYYY, YY, MM, M, DD, D, HH, H, mm, m, ss and s — covering year, month, day, hour, minute and second in padded and unpadded forms.

What input formats are accepted?

Anything JavaScript's Date can parse: ISO 8601, RFC strings, and common locale date strings.

What is the difference between ISO 8601 and RFC 2822?

ISO 8601 (2026-07-13T10:00:00Z) is the compact machine standard; RFC 2822 is the verbose email-header style used in HTTP and mail.

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