keep track
To know about changes; stay informed or up-to-date; keep a count or record.
What day of the week is it? I can't keep track.
Usually used with of.
Mr. Stevens kept track of his business by telephone when he was in the hospital.
The farmer has so many chickens, he can hardly keep track of them all.
Steve keeps track of all the long-distance telephone calls related to his business that he makes from his house.
With seven small children, how do the Wilsons keep track of all of them?