Germanic calendar inspired by the Julian calendar, introduced a purely solar reckoning with a year having a fixed number of weeks (52 weeks or 364 days). This necessitated the introduction of "leap weeks" instead of Julian leap days. The old Icelandic calendar is not in official use any more, but some Icelandic holidays and annual feasts are still calculated from it. It has 12 months, of 30 days broken down into two groups of six often termed "winter months" and "summer months". The calendar is peculiar in that each month always start on the same day of week. This was achieved by
Days of week on Hebrew calendar has 29 days and Kislev has 30 days). The months of Tevet and Shevat, months ten and eleven, have 29 and 30 days respectively. Finally, in a regular year the month of Adar has 29 days, while in a leap year Adar I of 30 days is added before the regular Adar, which becomes Adar II of 29 days. The result is that the period from 1 Tevet to 29 Cheshvan is fixed, except that in a leap year Adar I of 30 days is added; and all adjustments are made using 29/30 Cheshvan and/or 29/30 Kislev. The period from