The Sun takes 12 months, or a year to go through the Zodiac, spending 1 month or so in each sign.
There are four seasons; Spring (Aries, Taurus, Gemini) Summer (Cancer, Leo, Virgo), Fall (Libra, Scorpio, Sagittarius) Winter (Capricorn, Aquarius, Pisces)
If you live in South Africa or Australia, the Seasons are reversed meteorlogically, but not astrologically.
If you are born on the dividing dates (cusp dates), you may have to check the time to be sure that you are one or the other sign. And it’s either/or. What looks like an intermediary thing is that two planets, Mercury and Venus could be in either the previous sign or the next one depending on date of birth. Mercury is never more than 28 degrees away, and Venus is no more than 48 degrees away. So many people may have traits that are from the sign before or the sign after.
The Signs seem to follow the basic stages of life: Aries to Cancer-childhood. Cancer to Libra, young adulthood, Libra to Capricorn, full adulthood to middle age: Aquarius to Aries, old age and maturity.
An observation done while I had a radio show: news follows the Sun Sign. Just look at the headlines. And now to the first Sun Sign, the Point of Spring: