Machatzit HaShekel: What I learned this year

The minhag/custom with which we're acquainted is to collect Machatzit HaShekel on Erev Purim (Purim Eve), so I was confused when I heard that the guys at our office's Mincha (Afternoon Service) Minyan (10-man minimum for certain prayers--it's an Orthodox minyan, so they don't count women) collected Machatzit HaShekel on Taanit Esther/the Fast of Esther. But, on the other hand, it occurred to me that we would have a problem this year: We couldn't collect money on Erev Purim because it came right after Shabbat/Sabbath this year, and none of us would have any money with us, since it's forbidden to carry or use money on Shabbat. So when could we collect the Machatzit HaShekel (and, for that matter, the Matanot LaEvyonim/Gifts to the Poor also required for Purim)?

Chabad to the rescue:

"On Taanit Esther - the "fast of Esther," before the Mincha prayer, we give the Machatzit HaShekel. A Machatzit HaShekel is half of the standard currency of that particular country.

• It is customary to give three coins, since the word Terumah (lit. an offering) is mentioned three times in the beginning of Parshat Ki Tisa (Exodus 30:11-34:35). If one did not manage to give it before Mincha, then he can give it after Mincha, or before the Megillah reading on Purim night or before the Megillah reading on Purim morning."

I now have one Kennedy half-dollar (since the minhag in our congregation is to give only one half-"shekel") in my tefillin bag, for use tomorrow morning before the Megillah reading at our local synagogue, where my husband and I have each been chanting a chapter of Megillat Esther/the Scroll ("Book") of Esther for many years.