The year of 2021 will be the shortest year in decades. QIANTU
A year is 365 days long, the time it takes for the Earth to revolve (旋转) around the sun. However, every four years, we need an extra day to keep our calendar in sync (同步的). This is called a leap year (闰年). But 2021 isn’t one of those years, and yet it’s not behaving like a normal year.