Hello Ahmed,
Whether an accrual or deferral is done depends only on the posting date of the revenue flow with respect to its revenue period. Posted at the end of the revenue period it is accrual, posted at the beginning of the revenue period it is deferral.
Here is an example:
You have an interest flow of 30 EUR that is calculated from 1.1.-31.1.
1) If you post it on 31.1. and run TPM44 let's say on 21.1., then you will get an accrual of 20 EUR (for the period 1-21.1.).
2) On the other hand, if you post the same interest already on 1.1., TPM44 on 21.1. will calculate backwards from 31.1, so you will then get a deferral of 10 EUR (for the period 21-31.1.).
You can find more information in online document for customizing "Assign Update types for Accrual/Deferral)", Transitorische Abgrenzung -> Update type Deferral.
Hope this helps.
Best regards,
Jasmine