here is some info on a celtic calendar. I did not explore the site so I do not vouch for its veracity.

here is a fairly lengthy and detailed exploration of theories about the celtic calendar, including information,on this page and another, about the Coligny Calendar.

I may be opening myself up for scholarly presumptions, but but I might also add that in the Rosicruian Order, AMORC (Ancient Mystical Order of the Rosy Cross, or Rose-Croix), we begin our new year on the Spring Equinox, generally around March 21st. This dates from ancient Egyptian times. I'd have to look up more info in a reference volumne which is downstairs. I bring up later and do so if anyone is interested.

katlaughing