Apple Numbers '08 - Manual (Page 253)

Chapter 12 Dictionary of Functions 253
NOW
The NOW function gets the current date and time from the computer’s clock. Time
zones aren’t taken into account.
NOW()
 No arguments (but you must include the parentheses).
Notes
The displayed date and time are updated every time you open or modify your
document.
Whether you see the date, the time, or both depends on the cell formatting. See “Using
the Date and Time Format” on page 62 for more information.
You can use the TODAY function to get the current date; the value returned is
formatted to hide the time, which is always set to 12:00.
NPER
The NPER function calculates the number of payment periods for a loan or investment
based on fixed payments and a fixed interest rate.
NPER(rate, payment, present value, [future value], [when-due])
 rate: The interest rate per period.
 payment: The payment to be made per period.
 present-value: The present value of the investment.
 future-value: Optional; the future value of the investment or cash value remaining
after final payment. If omitted, future value is assumed to be 0.
 when-due: Optional; specifies whether payments are made at the beginning or end
of each period:
0 (or omitted) means payments are at the end of each period.
1 means payments are at the beginning of each period.
Notes
Be sure that the rate is expressed as the rate per period. For example, if the interest rate
is 10% per year and the payment period is monthly, the rate used in the function
should be 0.1/12 (approximately 0.00833 per month).
Examples
If your document is updated on October 4, 2008, NOW() returns October 4, 2008 10:47 AM unless the
cell holding the return value is otherwise formatted.