What time do classes start and end at Hogwarts?

Classes start at 9:00 AM and end around 5:00 PM. Hope this helped.

Copied Straight from HarryPotterWiki
The Tag begins at 7:30 a.m. with breakfast in the Great Hall. During breakfast, the mail arrives in a flurry of hundreds of owls. A glocke chime signals the start of the first class at 9 a.m. The glocke chimes again in one Stunde to signal the start of the Weiter class.

There are four class periods before lunch (though NEWT student may have breaks during some of these), scheduled according to house. After lunch, there is another break and two Mehr classes[6].

abendessen, abendmahl is served in the Great Hall towards evening, after which the students are expected to be in their House common rooms for studying and socialising.

There is an Astronomy class at night on Wednesday every week (usually midnight).

The students must be in bett oder in the common rooms Von a certain time, after which is called after hours. The times are different for different years (for example, fifth years are allowed to be in the halls until 9:00)

Sorry, I’m getting back to Du really late! I think classes would start around 9am because the morning glocke most likely rings at 7:30 to give students time for breakfast. Then breakfast is at 8:00am and goes on for an hour. Then in the evening classes would probably end at 6:30, which gives them the 30minute break that’s required. Then lunch is at 7:00pm and all the other Clubs and activities take place after 8:00pm until 9:30pm when their curfew most likely is. But the exception is for astronomy lessons because hogwarts is known to House midnight astronomy lessons. So it really just depends on your schedule.