What chronology system existed in Ancient Egypt, in Ancient Rome?

The ancient Egyptians used a solar calendar that had 365 days. But the year was divided into 3 periods of 4 months each.

The years were counted according to the time of the reign of the pharaoh, and the year usually began with the flooding of the Nile. This always happened on the same day, namely July 19.

In ancient Rome, the count was conducted from the date of the founding of Rome (750 BC). The years were also reprimanded for the reign of the emperors.

The calendar has changed several times. Under Julius Caesar, the year consisted of 10 months, so it became necessary to add another two months. The year was then lengthened by 151 days, and the new year began on January 1.

Emperor Augustus in 4 AD, he named the summer July and August in honor of the emperors, and every 4 years they began to add one day a year.