LCS support call 2305020050002383 was raised with the observation that a single personnel action (hiring a worker and assigning them to a position) results in different TZID offsets being stored across the three backend tables HcmPositionWorkerAssignment, HCMEmployment & HcmEmploymentDetails, with the first storing the users' timezone preference, whilst the second & third always store the UTC timezone despite the datetime values to which the offset is applied all holding the same value. As such, any application of the timezone across the tables would result in different offset values.

I'm told that this is because the form for HcmPositionWorkerAssignment is created through X++ form designer, with that engine handling record creation, whilst the HCMEmployment & HcmEmploymentDetails forms are created in code. This distinction doesn't clearly explain why a different offset would be desirable, so it seems reasonable to aim for consistency.