Zodiac Sign Dates Vary From Year To Year
While it would be more convenient if the Sun’s transition from one sign to another happened exactly at midnight on any given day, it doesn’t. Plus there are many various time zones throughout the world, so your midnight would not be the same as midnight for someone in a different time zone.
In addition, a calendar year is not the same as the Earth’s annual revolution (circling) of the Sun. The actual length of a sidereal year (time required for the Earth to revolve once around the Sun) is actually 365.25635 days. That is why every four years there is a leap year of 366 days to compensate for the error caused by the calendar year being shorter than the sidereal year.
This is why the Sun can be in different zodiac signs on the same calendar day in different years. The start and end dates of the zodiac signs can and do vary from year to year.
In reality the Sun was in one specific position, and therefore one specific sign, when you were born.
When your birth date falls near the end of one sign or the beginning of the next sign it is referred to as being “born on the cusp”. Before the age of computers it used to be very time consuming to determine your sign if you were born on the cusp.
Now there are online calculators that you can use to make this determination. You will get the most accurate results if you have all three of these:
1) your date of birth
2) your time of birth
3) your place of birth.
Most calculators will still allow you to calculate your sun sign without your time of birth but the determination could be off. Input these three items into an accurate online sun sign calculator and you will be able to confidently determine your Sun sign.