Modality

via thebearnose.com :

"Modality: Energetic characteristics of signs based on the seasonal order they fall into. There are three modalities: cardinal, fixed, and mutable. Cardinal signs (Aries, Cancer, Libra, and Capricorn) are the signs that the sun enters on a solstice or equinox. Fixed signs (Taurus, Leo, Scorpio, and Aquarius) are the signs that anchor the season: when the sun is in a fixed sign, it is solidly spring, solidly summer, etc. Mutable signs (Gemini, Virgo, Sagittarius, and Pisces) are the signs that the sun is in when the season is shifting. The suns passage through a mutable sign always ends on a solstice or equinox, when it moves into the next cardinal sign."

source: https://www.thebearsnose.com/astrological-glossary

http://astrostyle.com/learn-astrology/cardinal-mutable-fixed-signs/