Had a considerable cash this December in foreign country and if the wire does not arrive until 2015, can I claim the winnings for year 2015?

If this is not allowed, how would I be able to make any charity donations that can be written off for 2014?

Not sure if correct area to post this question. Any answers appreciated.

Is the wire coming from your offshore banking or poker account, or direct from the offshore casino? The principle would be "constructive receipt", which means the moment the funds are in your control, you have received those funds (i.e., as income):

http://www.irs.gov/publications/p538/ar02.html

So, if the money was given to you while you were in the foreign country, for example, and you are just in the process of sending it by wire transfer from your foreign account to your US account, then you have already constructively received the money and it is 2014 income.

If, however, you are awaiting your payout from the poker room which is coming by bank wire, you have not constructively received the money until it hits your account.

Charity is gratefully accepted.

Really appreciate this. Yes, I'm awaiting a wire transfer from the casino. The delay is certainly not caused by me.

There may be a finer point to consider. When you cashed, did you go to the cashier window and they gave you the choice to take the cash at that moment or have it wired to your bank? If so, then the money was "made available to you without restriction", and the bank wire was at your behest. Even though you are waiting now for the bank wire to arrive, you had constructive receipt at that moment.

If, however, you went to the cashier window and they said it would take 24 hours to process the payout, giving you the choice to come back for it or have it wired to you, constructive receipt did not take place.

It's shades of grey. Ultimately, you just have to be able to justify the way you report the income (in which year) should the IRS ask after you file. The fact that the money didn't arrive into your account until 2015 is pretty good justification. They probably won't ask, and they probably won't care as long as you pay the proper tax on that income, as well as the rest of your income.