May I know, is there any difference in terms of amount of interest gained if I self contribute on first day of the month vs last day of the month?

I read somewhere that interests are compounded daily, but at the same time there are also articles that say it's compounded based on the amount you have on the last day of the month.

Thank you for your clarification. So indeed it is based on last day of the month since there is one day of interest gained for the month we managed to get our deposit credited.