For those who want to calculate the interest, the formula is as such.
1) List down lowest End Of Day (end of day is wrong, the intra day balance is considered) balance for each month
2) Multiply lowest balance by interest rate for the account type and divide by 12 to get the monthly interest
3) Round each of the monthly interest to 2 decimal places
4) Sum up the monthly interest to get the final interest credited
Note that the bonus 1% interest is credited into SA
I was able to match the interest credited for my accounts and also against henrylbh calculations. Do reply if you are not able to match your interest credited.
If the above is correct, CPF interest calculation is very unconventional. Firstly, it takes the lowest balance of the month, secondly it does not consider day count and thirdly it rounds the interest at 2 decimal places each month
Edited away end of day balance