bug#80632: possible issue with date

UNCLASSIFIED - NON CLASSIFIÉ

Good day,

I noticed this behaviour of the "date" command today, and perhaps it is a bug, or it's by design.

Running date -date="-5 days 4 hours" produces the date minus 5 days from now plus 4 hours, whereas the intent is more likely to be "-5 days and 4 hours". I tried it with other numbers of days and hours and observed the same behaviour. Running date -date="-5 days -4 hours" produces the expected time.

I tried this using GNU date on the following systems:
Oracle Linux 9 on WSL on Windows 11,
Ubuntu 24.04 on WSL on Windows 11,
CentOS 9,
RHEL 7.9


Here is the output of one sample. The coloration is mine.

$ date --date='-5 days 4 hours' --debug
date: parsed relative part: -5 day(s)
date: parsed relative part: -5 day(s) +4 hour(s)
date: input timezone: system default
date: using current time as starting value: '15:18:38'
date: using current date as starting value: '(Y-M-D) 2026-03-17'
date: starting date/time: '(Y-M-D) 2026-03-17 15:18:38'
date: warning: when adding relative days, it is recommended to specify noon
date: after date adjustment (+0 years, +0 months, -5 days),
date:     new date/time = '(Y-M-D) 2026-03-12 15:18:38'
date: '(Y-M-D) 2026-03-12 15:18:38' = 1773343118 epoch-seconds
date: after time adjustment (+4 hours, +0 minutes, +0 seconds, +0 ns),
date:     new time = 1773357518 epoch-seconds
date: timezone: system default
date: final: 1773357518.401888226 (epoch-seconds)
date: final: (Y-M-D) 2026-03-12 23:18:38 (UTC)
date: final: (Y-M-D) 2026-03-12 19:18:38 (UTC-04)

The components of the -date= string are parsed individually rather than semantically (as spoken) and perhaps this is the intent and that's how most users use it and this is a non-issue. I wanted to bring it up just in case.

Thank you,


Khalil Hayek
(he, il)

Manager, Line-of-business Applications Management,
Surveyor General Branch, Natural Resources Canada

Chef, Gestion des applications dédiées aux lignes d'affaires,
Direction de l'arpenteur général, Ressources naturelles Canada
[email protected]<mailto:[email protected]> / Tél. 613-219-9418 / 613-350-6083

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