Yes, before days, I've always heard ON

Student or Learner
First of all Hello, and thanks for this good fourm
My name is Akram, i'm a new member here.
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Related to your topic
i choose "On" as i knew that the preposition "On" come before days.
but when thinking a while "since" can be choosen also and the persentage of since is more than on in the presence of specified time " A Monday".
Am i right ??
Yes, before days, I've always heard ON
thanks very much
it is "on" because the time. ( i think.....)
I chose ( On )
"Da doo ron ron" is a reference to song lyrics from a popular American song of the same title from the 60s, I believe, performed by The Crystals and later covered by Shaun Cassidy. The lyrics in question go something like, "I met him on a Monday and my heart stood still... da doo ron ron ron, da doo ron ron." It's just a meaningless "filler lyric," much like "doo wah diddy" or something else. :)
And yes, the preposition "on" is used for dates or days (of the week).
Actually, with reference to this particular example, the word since would generally only be used in a negative sentence with a perfect-tense verb, such as "I haven't met him since Monday." (Also, in spoken American English, we would almost always say, "I haven't seen him since Monday," not met.)
As for your question, since (and its counterpart for) have different uses than prepositions of time (on, in, at). Since and for are typically (but not always) used with perfect tenses, such as present perfect and past perfect (as well as their continuous forms).
You are correct to think that the word since is used with a specific point in time (such as a day or date), while for is used with a period of time, such as "three days" or "a month." However, neither of these words are interchangeable with prepositions of time.
nO doubt the answer is 'on Monday'.
on
thanks