The special project calendar is derived from the default system calendar, and should only contain project specific deviations.
Calendar is used for:
  • Escalation time calculation is using predefined Working hours
  • Burn down and up chart rendering considering only predefined Working days
  • No other feature considers currently these settings
See documentation...
Note: Hours is a comma-separated list of business hour periods in 24-hour format, e.g. "9:00 - 18:00" or "8:30 - 12:00, 13:00 - 17:30".
Default Business Hours
Special Calendar Days

There can be multiple definitions for the same day-of-the-week, for different periods Starting at/Valid Until the specified dates [MMM dd yyyy or yyyy-MM-dd].
Starting at Valid until Weekday Working Hours