Let’s be mindful of time. — We have a fixed amount of time, so please keep it short.
In the interest of time… — Because time is limited, I will skip this or shorten it.
We’re at time. — The scheduled end has arrived, and the meeting should end now.
I know we’re over, but… — An apology from someone who keeps talking after the end time.
Long story short… — I will skip the details and give the point.
Top of the hour. — The full hour, when most meetings start. Bottom of the hour is the half hour.