It's an intermittent fasting program
Basically, you only have a 5 hour eating window. you can choose the window you preffer. For example, if you use to have dinner in familly, you may want to have your eating window between 5pm and 10pm. Others preffer to eat earlier and make windows that include breakfast and lunch (e.g. from 8am to 1pm).
I did it once, but eventually I gave up because it was very hard on holidays, weekends and social situations that led me to change the eating window all the time.
I found the ideal for me was eating breakfast and lunch (I had a window from 9am to 2pm) and it worked short-term.
There are peopple who make it as a lifestyle maintenance program, but I feel my body wasn't made to starve durong evenings

However it works long-term for some
Hope it helped
x