Spring begins twice in March, depending on which definition you take. The Met Office starts it on the 1st for the sake of neat monthly statistics; the equinox, which is what most calendars print, comes around the 20th. Between the two, daffodils fill the verges, lambing gets under way on the uplands, and the evenings gain around four minutes a day.
March closes the first calendar quarter of 2026 on the 31st and takes the tax year to within days of its own end. That mismatch of five days between the two year ends is a genuine British peculiarity, inherited from the switch to the Gregorian calendar in the eighteenth century and never tidied up since.
March 2026 runs to 31 days and completes the first quarter of a year of 365 days. The tax year that began the previous April has less than a week left to run once the month ends, and the new one starts before April is a week old.