It may be a coincidence that the gym goes to work at one o'clock on the first day.
Most gym employees go to work around 10 in the morning and get off work around 10 in the afternoon. Gym is a service industry, and its business hours are different from those of ordinary enterprises and institutions. Because no one goes to the gym too early in the morning, many gyms are open at 10 or even1am in the morning, but they are relatively closed at night until about 10 in the evening.