|"Be Careful, Clara, that's a fine Specimen!" (Photo credit: Wikipedia)|
In ancient Roman times, the leap day was inserted after the sixth day before the calendas of March, essentially creating a second sixth day.
Hence bis-, two or double, plus sextus, sixth.
To make more sense of this, see what I wrote about it last Wednesday.
Also, an old tradition says that in a bissextile year (and only in a bissextile year), women can propose to men, and men are not allowed to refuse.
Although proposing might be a bit much, a woman asking a single guy* on a date would be a nice way to mark the tradition. Just saying.
* Like me.