Old English 13-month lunar year
In England, a calendar of thirteen months of 28 days each, plus one extra day, known as "a year and a day" was still in use up to Tudor times. This would be a hybrid calendar that had substituted regular weeks of seven days for actual quarter-lunations, so that one month had exactly four weeks, regardless of the actual moon phase. The "lunar year" is here considered to have 364 days, resulting in a solar year of "a year and a day".
As a religious tradition, the thirteen-month years survived among European peasants for more than a millennium after the adoption of the Julian Calendar.