The documentation of 'uxdlt cal' states in the examples that a range of years can be deleted from a Calendar:
Delete the years 2010 to 2016 from the calendar for the HEADQUART Management unit:
uxdlt CAL MU=HEADQUATER SINCE=2010 BEFORE=2016
However, the command 'uxdlt cal' with or without the SINCE and BEFORE parameters always deletes the entire Calendar
Defect
This issue will be fixed in a future version of Dollar Universe 7.
The reference for this fix is: DU_AS-7633