In
Impact in Changing Calendar - No difference in calendars
Dave points out what happens when the slices are recreated. That is what you are doing when you change the start date of the slices. Though next to allocations the number of availability slice records is higher than the number of any other type of slices weekly or other.
Just regarding the slices there is a CAW presentation by Kelly Limberg
and there was a four part series in this community
CA Clarity Tuesday Tip: Time Slicing 101 by Shawn_Moore (Rank: Guru) and a fifth part with practical examples
https://communities.ca.com/message/241702614#241702614
A further tip by Dave for monitoring timeslicing
https://communities.ca.com/message/13156632#13156632