Wfm bulk schedule import 400 bad request mapping zendesk agent shifts

Ran into a weird issue today with the workforce management api when trying to migrate our zendesk agent schedules. we are moving from zendesk’s custom shift app to genesys cloud wfm. the /api/v2/wfm/schedules/bulk endpoint keeps rejecting our json payload with a 400 bad request error. the error message says “invalid time format for shift start time”.

we are using iso 8601 format with utc offsets, just like zendesk uses. for example, “2023-10-27T08:00:00+02:00” for our paris timezone. this works fine in zendesk. but genesys cloud complains about the offset. if we remove the offset and just use “2023-10-27T08:00:00”, it accepts the data but assigns the wrong timezone, treating it as utc instead of cet.

we have tried using the /api/v2/wfm/schedules endpoint for single items too, same issue. is there a specific format genesys cloud expects for bulk imports that differs from standard iso 8601? or is there a known bug with the utc offset parsing in the current api version? we are on the latest version of the genesys cloud platform. any help would be appreciated as we are blocked on the migration timeline.