PERM Job Post Requirements-30 Day Period

Hi!

I am in a time crunch for PERM application. Prevailaing wage has been approved. My employer(HR) posted job order through SWA on Dec 15th. , whereas posting a newspaper add for the following Sundays (01/08/2023 and 01/15/2023). Does the 30 day period begin from the day SWA was filed or from the newspaper filing?
Please help me here as 20 days make a big difference.