Improve parsing of Date input formats

[hanbings]

There are 10 time parsing formats mentioned in the GNU findutils manual: https://www.gnu.org/software/findutils/manual/html_node/find_html/Date-input-formats.html

Include: General date syntax Calendar date items Time of day items Time zone items Combined date and time of day items Day of week items Relative items in date strings Pure numbers in date strings Seconds since the Epoch Specifying time zone rules

However, we currently only support parsing of General date syntax.

[tertsdiepraam]

This probably fits what we're doing in the parse_datetime repository!

[hanbings]

cool! It seems so. I would use it as a dependency to replace the existing parsing function. : )