Inconsistent 12hr/24hr time display on Shift Info page

[SebKuzminsky]

Expected Behavior

When showing pickup window start/end times, the robot should consistently use either 12hr "AM/PM" format, or 24hr format. It would be extra cool if the user could select their preference on the Settings page.

Actual Behavior

Both formats are used!

Steps to Recreate

Look at a shift info page, for example https://robot.boulderfoodrescue.org/schedule_chains/776

Environment

Chrome on Linux, but I don't think that matters.