The Second Empire counted years according to the Holocene Epoch (HE), the start of which was arbitrarily fixed at 12,000 BCE. Thus, CE dates can be found by subtracting 10,000 from HE dates; i.e. 20,724 HE = 10,274 CE.
The Second Empire year is 400 standard days. The year is divided into ten months of 4 tendays each.