Today, 5 July 2015, I am 24.18 years of age, says my script. See what I meant when I said I believe I'm younger than you? :-)
You can, if you like, specify a date of birth and have this script work out the age based on that, relative to the server time. Fill in the second date and it calculates the age as of that date.
Credits to John H. Robinson, IV, for noting that you have to put in a numeric month. Also, you can only use dates that can be represented as a
time_t value; therefore, do not use a date before 15 Dec 1901, or after 19 Jan 2038.