On 04/01/2026 17:41, Sylvestre Ledru wrote:
Hello
-d accepts some invalid inputs. For example:
$ /usr/bin/date -d "("
Sun Jan 4 00:00:00 CET 2026
The patch in gnulib rejects it, the other add a test in coreutils
with the patch:
$ ./src/date -d '('
date: invalid date ‘(’
Note that /usr/bin/date -d "[", ".", "^" already generate an error
(found with a differential fuzzer)
Well parenthesis are special in GNU date as (documented)
they can be used to introduce comments.
$ date --debug -d '2003(comment)-02-01'
date: parsed date part: (Y-M-D) 2003-02-01
date: input timezone: system default
date: warning: using midnight as starting time: 00:00:00
Also related is that the empty string is considered valid,
and interpreted as time 0 of the current day.
$ date --debug -d '' date: parsed number part: 00:00:00
date: input timezone: system default
date: using specified time as starting value: '00:00:00'
Also a single '(' is treated as comment to end of line
$ date --debug -d '1(ignore comment to eol'
date: parsed number part: 01:00:00
date: input timezone: system default
date: using specified time as starting value: '01:00:00'
So in combination the single '(' is treated like ''
I'm not sure we should change this.
Like some script may be defaulting to midnight like:
$ date -d "$optional_time"
cheers,
Padraig
