> The 25 is there in the name.
This largely depends on who you're asking? I don't know anyone who wouldn't consider 24 the course correct number of Advent, simply because that's the common number here (we celebrate Christmas on the 24th). So 12 makes perfectly sense, just do every second day.
There are also many groups who don't start on the 1st of December, but on the first Sunday of Advent. And probably many others.
Advent calendars are used to count down the days. Doing one every other day defeats the purpose.
How so? Advent candles increment once per week, which is even lower frequency.
I thought the purpose was to be a fun thing we used to kill time over the holidays
Christian holidays are not meant to be fun; literally, the whole theme is about sins, suffering and death (or in this case, being born into life of suffering and culminating with death).
I think the majority of people celebrating christmas are not doing so for religious reasons