commencement

noun

1. (countable, uncountable)The first existence of anything; act or fact of commencing; the beginning.

   “The time of Henry VII nearly coincides with the commencement of what is termed modern history.”

   “Yet from the commencement of mining there have been unnoble proprietors of mines, who belonged to the class of merchants.”

   “Commencement of a two-hourly service pattern by GWR marked the return of regular services to Okehampton for the first time since their withdrawal in 1972. There are plans to extend this to hourly.”

2. (countable, uncountable)The day when degrees are conferred by colleges and universities upon students and others.
3. (countable, uncountable)A graduation ceremony, from a school, college or university. Sometimes before the actual graduation.