T.C.S.

TCS has to deposited within 1 week from the last day of the month in which amount is either debited or received whichever is earlier. (Refer Rule 37CA).
In case of late deposit, Interest shall be charged @ 1% per month or part thereof on the amount of such Tax from the date on which such tax was collectible to the date on which the Tax was actually paid. (As per Sec. 206C (7)

within seven days from the end of month in which credited or paid whichever is earlier.

It is on the 7th of the seccedding month