We must give Matanot L'Evyonim on the day of Purim. We can do it via a Shaliach. If we give to a Shaliach to use in Israel for example, If they give out the money at 8 Am it is only 1 AM in North America, so we are not yet fulfilling the mitzva. If they use the funds after 3 PM (i.e. on Purim), then it is day in America and still Purim in Israel so that the Matanot L'Evyonim is being used for Purim and we would have fulfilled our obligation and no further donation would be required on Purim in America (I think). But, if the funds are used in Australia then, when they have their seuda it is either night in America or still Taanit Esther? So how could we be fulfilling giving Matanot L'Evyonim on Purim itself?
In this case, it would be given from America when we are not obligated AND used in Australia again before we are obligated. By the time morning arrives in America, Purim is over in Australia or China (unless I guess the seudah there continues throughout the night?). So would one fulfill the mitzvah of Matanot L'Evyonim via this Shaliach who gave the money to Australia or China? If we sent a cheque, then there is no Shaliach and we could not say that the Shaliach is simply an extension of "us" as if we are there so the question remains.
Do we fulfill the mitzvah of Matanot L'Evyonim if we send money for this purpose to Australia or other areas who experience night when we have Purim morning either via a Shaliach or "direct deposit"?