Correctly handle DST for service runs (daily interval only)

Checking the time stamp at midnight and comparing those does not work across DST, as we'll have 23 hours passed instead of 24, causing the update to potentially not run.

Work around this for daily intervals by comparing the date instead. This still ensures we only run once a day, while being save of any time zone shenanigans.

This will not help users that have non-default intervals configured, however. It's unclear if a more generic solution exists that can cater to those users.

LP: #1824088