Pension Allowance - limits and dates

For Pension Contribution Annual Allowance, which is the date that matters when submitting a tax return? I salary sacrifice through my monthly payslip, and it typically lands in my workplace group pension 6 weeks after payroll. But for some reason last tax year April payment went through on the 2nd instead of the 19th as expected. So from a WGP perspective it looks like I have 13 payments in the year rather than 12 as expected. So which date do I need to take for my annual allowance limit calculations? The date I got the payslip, or the date is actually lands in my workplace pension?

Hi,
Please refer to PTM041000 - Contributions: essential principles Deemed date of contributions
Thank you.