Causes Of Four Seasons:
Spring - When the sun is directly overhead the equator (Start Date - 21st March)
Summer - When the sun is directly overhead the tropic of cancer the north temperate zone experience summer (Start Date - 21st June)
Autumn - When the sun returns to the equator and the north temperate zone experiences the season of autumn (Start Date - 23rd September)
Winter - The sun is at the tropic of Capricorn and the north temperate zone experiences winter (Start Date - 22nd December)