[Conradus]

Have you tried my solution?

pawn Код:

stock AddCommaAfterMonth(DateString[]) {
    new Day, Month[3], Year;
    if(sscanf(DateString, "dsd", Day, Month, Year)) { 
        print("Comma could not be added to the Date String (Reason: string not in the right format)");
    }
    else {
        format(DateString, sizeof(DateString), "%d %s, %d", Day, Month, Year);
    }
    return DateString;
}

If we assume your date string is in the variable DateString, you can now just add the comma like this:

pawn Код:

DateString = AddCommaAfterMonth(DateString);