A candidate is saying they cannot produce an adhoc timesheet for a shift worked more than 3 weeks ago, what can we do?

This deadline has been fixed to discourage extremely late timesheet submissions, and any workarounds remain entirely at your organisation's discretion. If your organisation is happy for the timesheet to still be submitted, and it needs to be submitted electronically, then the candidate may submit the timesheet for a date that falls within the 3-week window and mention in the comments section the date that the shift was actually worked.