does it matter when I pay extra on my mortgage?

My mortgage is due 1st of the month but like most everyone, i have a few weeks grace period. I usually pay it on the 10th to give myself some time to transfer money to account for weekends and holidays and such. I occasionally will pay a few thousand extra but I like to wait til at least the 15th when I get paid. my question is, does it matter when I add the extra pay? I'm told so long as I pay it after my regular monthly payment settles (so like the 11th or 12th if I pay on the 10th) and before the start of the next payment (so 1st of the next month), lump sum will all go to principle but is there any extra interest calculated on my mortgage the longer I wait for the lump sum in btwn those periods?