Year-end gift credit may require some extra planning to insure your gift is credited for tax purposes in the current tax year. IRS regulations stipulate that contributions sent by private carriers must be dated based on the date of receipt by the charity, whereas gifts sent through the US Postal Service can be dated and receipted based on the envelope’s postmark. Online gifts must be received by December 31 at 11:59 p.m. in the timezone where your taxes are filed to be counted within the same tax year.