Meaning of the word "commencing on" in English

What does "commencing on" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

commencing on

US /kəˈmɛnsɪŋ ɑn/
UK /kəˈmɛnsɪŋ ɒn/

Phrase

starting on a particular date or at a particular time

Example:
The new policy will be effective commencing on January 1st.
Classes are scheduled to resume commencing on Monday.