isMorning variable refers to $\text{'}$am$/$pm$\text{'}.$ The time in the first parameter will just be hour number in the $12$ hour format.

example$-1--$ if isMorning $=$ true and hourOfTime $=11,$ this refers to $11$ am

example$-2--$ if isMorning $=$ false and hourOfTime $=10,$ this refers to $10$ pm