In Clarity Modern UX the periods are managed differently via fiscal periods.
Is there a different way to get data from database for example 'Allocation' and 'ETC' or can I still use the Time slices tables to get data?
Release : 16.2
The Time slices as they exist today are still valid and can still be used, however you should use the fiscal slices instead.
These are held in the PRJ_FISCAL_BLB_SLICES table.
You can query the PRJ_BLB_SLICEREQUESTS table or look in the UI under Admin / Data Administration/ Time Slices to find the corresponding fiscal slices you need.