The Irish calendar does not observe the typical astronomical seasons (beginning, in the Northern Hemisphere, on the equinoxes and solstices), or the meteorological seasons (beginning on March 1, June 1, September 1 and December 1), but rather centers the seasons around the solstices and equinoxes (so that, for instance, midsummer falls on the summer solstice), beginning the seasons at the approximate halfway points between solstice and equinox, following the seasons of the ancient Celts (see below) which are pre-Christian in origin. This Celtic origin is particularly evident in the Irish naming of many of the months: some names, like May (Bealtaine), August (Lughnasadh/Lúnasa) and November (Samhain) were the names of pagan Celtic festivals. In addition, the names for September and October