Arduin days are exactly 25 hours long, consisting of ten full hours of daylight and darkness, with two and one half hours each of twilight and dawn. There is no axial tilt or rotational wobble, so this never varies during the year regardless of the season. The day of Arduin is also called Zed, and its hours are known as Azark. An Azark further breaks down into Azar (minutes), Aza (roughly 9 seconds), and Az (approximately a second). Six days comprise a week, usually called a Sixday or Zedra. The individual days of the Zedra are Mordag, Taenwal, Wurdigan, Veldoar, Sarmaht, and Qwain, in that order. The folk of Arduin commonly work Mordag through Veldoar, and half a day on Sarmaht, taking the afternoon and all day Qwain off. This varies regionally.
There are 15 months in the year, for a total of 450 days in the year, not including Tai Taowyn or End Year, which is a five-day period of ‘non-time’ that takes care of the odd orbital period around the sun of 455 days (its our equivalent of Christmas!). The months, in order, all called: Tor, Ator, Vaen, Torvaen, Kos, Torkos, Skord, Torskord, Zar, Torzar, Ghast, Torghast, Chund, Torchund and Khoros, or the End Year month.
There are four distinct seasons: Summer, Fall, Winter, and Spring. Winter is 125 days long, and is the last 25 days of the old year and the first 100 days of new. Spring follows with 125 days and is in turn followed by 125 days of summer. Fall follows as the first 75 days of the last one hundred days of the year (the first 25 days of winter being the last 25 days of the year.