The First Day of Spring
The Vernal Equinox (the Spring Equinox) occurs on March 20. On that day the sun is directly above the earth's equator and daytime and nighttime are of equal length.
After this, the days become longer than the nights for everyone north of the equator until the summer solstice.
There are many ideas associated with the arrival of spring. One of the stranger myths is that eggs will stand upright on this day due to "everything being in perfect balance".