Komaru tracks time according to the procession of the heavens. Mourn's sun completes one revolution every 400 days. Years are counted from the beginning of ages; the current age is Paraceln's. For convenience, this solar year begins with the spring equinox and is divided into 25 16-day months, during which time the bright moon Lucien waxes from new to full and back. Months are further divided into two eight-day weeks, known as the Waxing and Waning according to Lucien's state. The Mournish day is 25 hours long.

As an example of a Mournish date, Crown Prince Alessandro Komaru was crowned on 8 Waxing of the 15th Month of the 204th Year of Paraceln's Age. More conveniently, this can be represented as 8 Waxing of 15, Paraceln 204.