Apple Numbers '08 - Manual (Page 282)

282 Chapter 12 Dictionary of Functions
TIMEVALUE
The TIMEVALUE function converts a date, a time, or a text string to a decimal fraction of
a 24-hour day.
TIMEVALUE(date-time)
 date-time: A date, a time, or a text string in any of the Numbers date and time
formats.
Notes
To convert a time that is formatted as a time value instead of a string, use the TIME
function.
TODAY
The TODAY function gets the current system date and formats the cell to display just
the date, not the time. The time is always set to 12:00.
TODAY()
 No arguments (but you must include the parentheses).
Notes
The displayed date is updated every time you open or modify your document.
You can use the NOW function to get the current date and time already formatted to
display both.
Examples
TIMEVALUE("4/6/88 12:00") returns 0.5 (noon represents one-half of the day).
TIMEVALUE("12:00:59") returns 0.5007 (rounded to four decimal places of accuracy).
TIMEVALUE("9:00 pm") returns 0.875 (21 hours, or 9 PM, divided by 24).
Examples
When calculated on April 6, 1988, TODAY() returns Apr 6, 1988.