The year is not needed in date references within the current 12-month period: The next meeting of the Executive Council will be on Oct. 22.Grant applications are due July 1. An exception might be for a formal event program or invitation.
When referring to a past or future year, include the year. Set off with commas if including a complete date: The target completion date for the project is Aug. 15, 2030, which will be 10 years after it started.
Use an ‘s’ with no apostrophe to indicate a span of decades or centuries: the 1960s, the 1700s.
Use an apostrophe before the year when abbreviating the reference: the ‘60s.
No apostrophe is needed after descriptive decade references: a 1930s bungalow, a ‘50s vinyl record
Years are an exception to the ‘numbers’ rule that figures cannot start a sentence: 2020 was a difficult year for many.