20+ date format conversions.. Date Format Calc is a free online tool from the ToolsRift Developer Tools collection. It runs entirely in your browser — nothing to install, no signup, and your data never leaves your device.
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.
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.
Anything JavaScript's Date can parse: ISO 8601, RFC strings, and common locale date strings.
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.