This is a later and improved method used as a calendar to follow the solar year through the seasons. Shown here is another calendar, and an easy method of telling the time of year, and predicting accurately the solstice day and time. The system follows the days in a season, from equinox to solstice, and vice-versa. Seasons vary from less than 88 days to more than 93 days, making a scale of 90 divisions the most convenient. By measuring movement over some days and taking ratio to an equal number on scale, it makes for an accurate prediction.
Ggantija North is adjacent to an older calendar, both having nearly same orientation. However the equinox to solstice angle in the later unit is 18deg, as against a previous 23deg in the older one. Reason for building a second unit on same orientation. Date: just after ~3550bce. Ggantija North became suddenly obsolete due to the 3200bce event.
The scale of 90 divisions to the quadrant gives a 360 division of the circle. Subdividing the quadrant by its radius, in 3 parts, gives a circle division of 12.
View the main solstice stones here courtesy Google Earth: https://firstname.lastname@example.org,14.26913,3a,90y,353.28h,103.57t/data=!3m8!1e1!3m6!1s-C4E_yNv9veg%2FWJvFqfbHipI%2FAAAAAAAALio%2Fu3IRmda5rCoh0mnR3k4s3EuzsTixkFEJgCLIB!2e4!3e11!6s%2F%2Flh6.googleusercontent.com%2F-C4E_yNv9veg%2FWJvFqfbHipI%2FAAAAAAAALio%2Fu3IRmda5rCoh0mnR3k4s3EuzsTixkFEJgCLIB%2Fw203-h100-k-no-pi-0-ya264.65637-ro0-fo100%2F!7i5376!8i2688?hl=en-US