Fix date filter on global time tracking report

Report run for 2023-08-16:

Variables using UTC date (so 2023-08-15T23:00:00 UTC is the same as 2023-08-16T00:00:00 BST):

Results returned only include records from 2023-08-15T00:00:00 -> 2023-08-16T00:00:00: