#3170·dayjs

duration humanize ignoring leap years

Author: zac-robinsonCreated Aug 6, 2026Updated Aug 6, 2026

Describe the bug I called dayjs.duration("P9999Y").humanize() and was returned 9992 years If I call dayjs.duration("P9999Y").asYears() then I get 9999.

Expected behavior Expected that on large durations then humanize returns the same number of years as .asYears().

Information

  • Day.js Version: v1.11.21
  • OS: Mac OS
  • Browser: Brave v1.93.132
  • Time zone: BST