Hello lally,
here is a simplified example that hopefully helps clarifying things.
Setup two accrual schemes - one with calender, the other one with fiscal.
Note that the fiscal year of the Company differs from the calendar year.
Record an invoice for 12000$ and make use of the accrual schemes => outcome is identical if the start date is the beginning of the fiscal year (01 April)
If the start date is 17 July, the calendar accrual scheme works as usual /expected.
Yet, the accrual scheme that refers to the fiscal year, comes up with the following result.
I would thus always go for the "calendar" option.
Does this make things clear?
If not, I would suggest that you setup some similar accrual schemes in a demo/test environment and do some additional testing to identify what might fit best for you.
Best regards,
Ludwig