World's longest year

We hope you did not answer any of the many leap years as you would be way off.

In 153 BC the Romans set the new year as January 1st, but set it at 355 days.

A bit later they reverted back to celebrating the new year in March.

Finally in 46 BC Julius Caesar created the the Julian Calendar and the new year was to fall on January 1st again and last 365 days.

Unfortunately the calendar was out of sync and an extra 90 days were added to 46 BC making it the longest year ever clocking in at 445 days.