Fix datetime shift in job filter for non-UTC timezones

[otariidae]

Problem

When Rails.application.config.time_zone is set to anything other than UTC, the datetime in the job filter shifts incorrectly each time it's edited.

For example, in my application where the timezone is set to Asia/Tokyo (+09:00), the time increases by 9 hours with every input.

time-zone-auto-shift.mov

Cause

The likely cause is how the datetime string is parsed.

The form.datetime_field submits a datetime string in the %Y-%m-%dT%H:%M format, which is then parsed by DateTime.parse. However, regardless of the application's time zone setting, this method defaults to parsing the string as UTC when no time zone information is provided.

Solution

This pull request fixes the issue by parsing the datetime string in the application's configured time zone.

[rosa]

Good catch, thank you!