You are letting someone know that something is required to be done at the present time.
Here are some examples:
“It’s time to say goodbye.”
“It’s time to ask for a raise.”
“It’s time to collect our money.”
“It’s time to cheer for our team.”
“It’s time to change the clocks.”
“It is time to decide what to do.”
“It is time to enjoy ourselves.”
“It is time to fill me in on what’s going on.”
“It is time to help out.”
“It is time to join a gym.“