Existing holidays decrement by one day when adding a new holiday to an SLA calendar

Issue Summary

When creating and saving a new holiday to a calendar with existing holidays, the dates of the previous holidays decrease by one day (they go one day into the past). e.g. New Year's Day (January 1) changes to December 31 after adding an additional holiday.

The problem can also be triggered by modifying the Working Hours for the calendar and clicking Save. 

Steps to Reproduce

1. Create or modify a calendar for an SLA
2. Add a holiday
3. Save the calendar
4. Edit the calendar and add another holiday
5. Save the calendar again
6. Edit the calendar again to observe the dates on the holidays - the holiday created in step 2 will have decremented its date by one day

Expected Results

Previously saved holidays remain on the correct date.

Actual Results

Previously saved / existing holidays have their date set backward by one day. This continues for each additional time the calendar is saved. For example, a holiday on January 5 will move backwards to January 1 if four more holidays are added to the calendar (and saved individually).

Workaround

Disable the new Calendar view (introduced in Service Desk 4.4) via Dark Feature:

• Go to the darkfeature page: <Jira_URL>/secure/SiteDarkFeatures!default.jspa
• Add the following feature:

  sd.workinghours.new.page.disabled