No article is used in English for a noun that denotes a time of day. The exceptions are:
- When the noun is modified by an adjective, e.g. "a wild night".
- When it's a time of day from a specific day that is clear from the situational context, e.g. "I woke up. The morning was cloudy".
- When it's a time of day from a specific day that is clear from the linguistic context, e.g. "the day we met".
- The phrases "in the morning", "in the afternoon", and "in the evening". Note that the phrase "at night" is preferred when talking about nighttime.