Die Zeitrechnung

Yes, the Auran Empire has a specific calendar.
The calendar actually predates the ACKS system. When creating the calendar, I wanted a calendar that would (1) have months of the same length, (2) have every day of the week always fall on the same date in each month, (3) have the lunar and solar months be of equal length, and (4) keep the 7-day week. That way I always would know for any year and date what day of the week it would be, and what phase of the moon. This is great for tactical-level play - if the adventurers wanted to adventure “on a moonless night” I always knew when that would be. If they wanted to set off “on a holy day for Ammonar” I always knew when that would be.
I made the system work by going with 13 28-day months. The downside is that technically the seasons are each 3 months and 1 week long, rather than being 3 months long. This creates some tension with the season system min ACKS. In using the calendar for ACKS, I resolve this by having domain morale checks every 3 months, with a bonus check on Celebration of Unconquered Dawn, figuring that it’s the major holiday of the year.
I may tweak the system again before final publication of the Auran supplement.