سؤال إلى أهل العلم افيدونا؟!!

since: is aalways followed by : a name of a day , a name of a month, year , century e.g. since Monday, since March , since 1996 , since the 13th century .it’s also folowed by a clause e.g. I have been sleeping since i called you.it’s also followed by a time e.g. since 3.00pm
for is followed by a number of days , months , years, hours, centuries ,a phrase of time ……e.g. for 2 days, for 3 months , for 6years , for for 8 hours, for two centuries, for a whole weekend , for a day