Using time in HMS as a regressor

For my dataset, I am trying to use the time an event occurred as a regressor term. Lets say I have a dataset of people who rent bikes. I'm trying to forecast how many people will rent a bike.

If people rent bikes at different times during the day, can that be used as a regressor? Let's say bikes can only be rented at specific times during the day, e.g. 8:15am, 10:30am. So using this as a regressor term for number of people who rent a bike in a day

If possible, how would you treat such a term, I have been trying but i've been getting the issue
`You have provided a name that is not syntactically valid in R`

Thank you!