Is it ok to make charity today (ie. in advance) knowing that exact interest amount that shall be credited in my bank account at the end of year?
The majority opinion regarding the advance payment of zakat is that it is permissible, although the scholars differ as to how far in advance (e.g. one year, or more than one year) it can be done. I know of no reason why the same ruling cannot be applied to the purification in advance of one's wealth if one can reasonably predict gained interest.
However, it would still be important to ensure that, at the end of the year, the amount purified actually meets (or exceeds) the amount earned.
Look at the verse below from the Quran
Oh you who believe! Fear Allah and give up what remains of your demand for usury if you are indeed believers.
If you do not, take notice of war from Allah and his Messenger but if you repent you shall have your capital sum. Deal not unjustly and you shall not be dealt with unjustly. ( Quran 2:278-279 )
Please see the bolded phrase "take notice of a war from Allah and His Messenger". I have not seen any sin in the entire Quran that is given this sort of punishment.
Do you know what this means? It means you will be battling a lot of things in your life. The money will not let you live in peace.
Unfortunately even after such clarity, the sin of riba has crept deep into the Ummah.
I beg of you to please stay away from this sin. It is a loosing battle.
Some people donate toilet slippers with riba money, some people give zakat. Those are all ways to just make us feel nice, but in reality it is good that we just turn our faces to this sin.