If I remember correctly, I tried to place for this when this firecracker Chinese New Year TIA-i promo was mentioned. However, I aborted as the placement as the promo was cut short in only a few days and the rate dropped to 2.40 % instead of the advertised 2.45 % for 11 -26 Feb 2021.
I believe by 17 Feb 2021, the HLIB TIA-i p0m6 rate was already down to 2.40 %.
For RM 5,000, you should get exactly 5000 x 181/36500 x 2.4 = RM59.50. You will not get RM 59.51 because HL Bank is one of the banks that uses the Round Down Nearest Sen (rdns) method for rounding, compared to other banks that use Round To Nearest Sen (rtns) method. If you keep proper records and calculation, you can discover how each bank calculates profits/interests.
If somehow you can prove in the receipt that it was 2.45 % at the time of placement, then you can ask the bank to correct it.
You can then get 5000 x 181/36500 x 2.45 = RM 60.74 rdns and not RM 60.75 rtns as profit.
There are 181 IBD from Effective Date 17 Feb 2021 to 17 Aug 2021, and HL uses 365 divisor for all years.
Effective Rate is simply a rough guide and always off (wrong) because it is a simplification that does not take into account the distorting nature of calculating interest based on Interest Bearing Days (IBD). This is one of those instances where the common understanding/calculation is always 100 % wrong all the time because it is just arithmetically impossible.
What you are trying to determine is not called Effective Rate which is a % per annum. It can be termed Actual, Real, Paid, Collected, Return or Yield rate on your principal (depending which math, finance book, or author you read or follow}.