Mars scientists have a convention that the year starts at L_s = 0°, which is the vernal equinox in Mars’s northern hemisphere.
The next Martian new year by this convention starts on Earth date 2021-02-07, and lasts through 2022-12-25 (Christmas day!).
Interesting that they didn't go with what we base it in Western society, essentially the winter solstice. That said I've always thought the vernal equinox makes more sense.