WFMW ~ Backwards Edition ~ Sending out Birthday Cards

I love the idea of always getting Birthday cards sent out to family and friends but so far I haven't been very successful. I was wondering if any of you have any tips of how you stay organized with that and how you remember to get them out on time?
I do have dates written on the Calendar and I usually make all of my own cards, I have some made ahead of time or I have the stuff to make one quickly. The issue I have is getting them in the mail and also turning the calendar up for a new month and then remember that my Mother-in-laws birthday is on the 2nd and now it is way to late to send her a card.

Anyway, what are your suggestions?
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