The great debate: When does spring officially start, February 1 or March 1?

A St. Brigid's Cross hangs from a tree at St Brigid's holy well in Co Kildare. February 1st marks St Brigid's Day which is seen by many in Ireland as the first day of Spring. Picture: Brian Lawless/PA Wire
Most Irish people believe that today, February 1, and St Brigid's Day, marks the start of spring.
This belief stems from a traditional Gaelic festival called Imbolc.