Timekeeping

The Faerûnian calendar is extremely elaborate. I've been trying to keep track of when things are for my adventurers, and it's really hard!

It doesn't line up very well with our calendar and I can't figure out when the seasons should start to change.

The months are:

• Hammer
• Alturiak
• Ches
• Tarsakh
• Mirtul
• Kythorn
• Flamerule
• Eleasis
• Eleint
• Marpenoth
• Uktar
• Nightal

Great fantasy names. However, the solstices and equinoxes don't line up, they're all a month later than I want them to be. If Nightal is December, then the winter solstice should go between Nightal and Hammer, but it's between Hammer and Alturiak instead.
So, when does spring start? March is the third month, but it also has the vernal equinox in it. And the spring equinox is between Tarsakh and Mirtul.

It's annoying.

My players are in Ches now, I think I'm going to declare that spring is starting anyway though.