Sign-up / advanced user-defined timeslot options displays default start/end times

When using advanced time slots, the populated start/end dates does not show the previously updated start/end dates, but the default start/end date.

To replicate:

1. Select the Sign up tool
2. Select Add 
3. Enter title/location and set the start time/end time to a day or two in the future.
4. Select the checkbox for "Advanced user-defined timeslots"
5. Press "Create Timeslot(s)"

The custom timeslots page loads, but populates with the original start/end dates in the tool instead of the updated times.