Time Functions and Formulas in Excel (part3)
NOW(): shows you the time.
WEEKNUM(): gives you the weeknumber
This very useful to indicate the weeknumber of a date.
YEARFRAC: gives you the fraction of the year between two dates
YEARFRAC is a useful function to rapidely calculated the fraction of the year between two dates.
For example you want to know what fraction of the year is between 1 march and 31 mai. YEARFRAC("1/3/2015", "31/5/2015") gives you exactly 0.25 or a quarter of a year.
Here some examples from january first.