# EPUBCheck OPF-053: Date value … does not follow…

Source: https://epublab.com/epubcheck/opf-053/ (updated 2026-11-03)

EPUBCheck OPF-053 is a warning message: “Date value "…" does not follow recommended syntax as per http://www.w3.org/TR/NOTE-datetime:….” A date in the metadata does not follow the recommended format (W3C date and time), so some apps may not read it.

- Official message (EPUBCheck 5.4.0): Date value "%1$s" does not follow recommended syntax as per http://www.w3.org/TR/NOTE-datetime:%2$s.
- Default severity: Warning

## Typical causes

- Dates written as text or in local formats, such as "March 2020" or "03/15/2020".

## How to fix it

- Write the date as YYYY, YYYY-MM or YYYY-MM-DD, for example 2020-03-15.

Message text and severity: EPUBCheck (W3C, BSD-3-Clause). Explanation: EPUBLab.