Do you follow the exact day year year for a Sabbat, or do you go with the astronomical time that changes with each year?
And why do you celebrate on the date that you do?
I am torn between a set date that is the same every year, which makes things easy to remember, and the astronomical date, which I usually go by.
I use whatever date my coven uses, of course. New to the Wheel of the Year stuff.
Makes me wonder if the Pagan calendar is solar or lunar? I’m used to the Jewish
calendar which is lunar and that’s got problems too. Holidays move around year to year,
and you need to add leap months. A whole month, seven of them in a 19 year cycle,
It’s confusing.
Merry Moday Sedim,
I also had issues with the dates and how to approach them. As like most of the craft, it is more about intent than “rules” such as dates, candle color, words….. For myself, I am a solar (hmmm does being in the desert have anything to do with that? Vegas, Baby, Vegas 
) I pretty much follow the Gregorian calendar with the Pagan dates too. I do not do moon veneration. I approach the moon in my dawn oblations, and before I lay down at night. For the Imbolc, Feb 1-2—-I will address that the holiday on the 2nd, in the morning. This way, I have the “start” from the evening before and veneration for the day. I do not stress about the specifics, because most of what is out there is NOT “exactly” what our ancestors did. It is not about how many times you turn around (avoid vain babblings, such as the heathen do….something like that in one of the gospels of Jesus). So, what and when, is not as important as content, your intent!! If you do it with your whole being and conscious, it is good “in the sight of” the ladies. So, bottom line, do not worry about the “what” or “how”….just do it with all your “heart and soul” and the cosmos will reward you by listening. Hope this helps you out.
Lady Gene 
It really is up to you - there is no hard rule set in stone in the vast majority of pagan traditions that say you MUST celebrate a given holiday on a certain date. We live in crazy modern lives - as long as you can make it work within your schedule, and it fits your practice, it’s all perfectly alright..
I used to follow a hybrid of the Celtic and Norse/Germanic calendars - and I typically followed the astrological timing too. It felt more authentic at the time to have the real thing happening in the sky. But recently I switched my practice over to something entirely different, so sabbats aren’t even on my calendar anymore.
To answer your question Sedim, the answer is both, most of the time. Most pagan calendars are lunisolar - following the solar events of solstices and equinoxes, and the quarterly lunar seasons.
Cheers.