Dates and times
AI agents: read /llms.txt; add .md to any page URL. This page as Markdown: /concepts/dates-and-times.md. Index of every page and the rules for every call: /llms.txt. Guides and concepts in one file: /llms-full.txt. OpenAPI: /openapi.json.
YoPrint stores every date-time in UTC. People see them in their own timezone.
Send and read UTC
Section titled “Send and read UTC”- Send date-times in UTC, in ISO 8601, ending in
Z:2026-11-03T15:00:00Z. Some fields accept an offset such as-07:00, but others keep the clock time you send and drop the offset, soZis the only form that’s right everywhere. - A date alone, such as
2026-11-03, means midnight UTC on that day. - Read date-times back as UTC, and convert them to the shop’s timezone to show them.
A day in the shop
Section titled “A day in the shop”A shop’s Tuesday doesn’t start at midnight UTC. Convert the start of its first day and the end of its last day, in the shop’s timezone, to UTC:
- The shop's daysTuesday 3 to Thursday 5 November
- In the shop's timezone00:00:00 on the 3rd to 23:59:59 on the 5th
- In UTC
2026-11-03T05:00:00Zto2026-11-06T04:59:59Z
Schedules are whole days
Section titled “Schedules are whole days”The web app schedules jobs and tasks in whole days, in the person’s timezone: from 00:00:00 on the first day to 23:59:59 on the last, sent as UTC. Do the same, and your schedules line up on the shop’s calendars. See Production.
Where dates count days
Section titled “Where dates count days”Filters don’t take dates. A date condition’s value is a whole number of days from today, counted in UTC days, and a date string is refused with 422. v1 and v2 filters count the days differently, and neither lines up with your shop’s days. See Dates are days from today.