Sabbats & Esbats
Brief Explanation:
There are at least 21 times a year in which Wiccans perform religious rituals. These can be broken down as:
8 Sabbats, or Solar festivals-these being God orientated
13 Full Moon celebrations-usually Goddess orientated
You will find that most of the Sabbats seem near the same time as Christian holidays. This doesn't mean that Wicca "copied" holidays from Christians, Wiccan rituals are based on ancient religions that predate Christianity by thousands of years.