Today is the current day. Today begins with this morning. Then we have this afternoon, this evening, and tonight
Yesterday is the previous day. Yesterday begins with yesterday morning. Then we have yesterday afternoon, yesterday evening, and last night
Tomorrow is the following day. Tomorrow begins with tomorrow morning. Then we have tomorrow afternoon, tomorrow evening, and tomorrow night
We have some other basic time phrases in English
- in the morning
- in the afternoon
- in the evening
- at night
Exactly 12:00pm is noon
Exactly 12:00am (0:00) is midnight
The time period between 12:00am and about 4:00am is in the middle of
