Time Representation
The time component of a serial value ranges in value from 0–0.99999999, and represents times from 0:00:00 (12:00:00 AM) to 23:59:59 (11:59:59 P.M.), respectively.
Going forward in time, the time component of a serial value increases by 1/86,400 each second. (As such, the time 12:00 has a serial value time component of 0.5.)
TIMEVALUE("00:00:00") results in the serial value 0.0000000…TIMEVALUE("00:00:01") results in the serial value 0.0000115…TIMEVALUE("10:05:54") results in the serial value 0.4207639…TIMEVALUE("12:00:00") results in the serial value 0.5000000…TIMEVALUE("23:59:59") results in the serial value 0.9999884…