Ever want to know how many seconds old David Hasselhoff is? calc can do many things, but it doesn’t know much about Hasselhoff, so first I do a query on Google for [david hasselhoff]. I get a knowledge card on the right saying he was born July 17, 1952. It doesn’t give a time, so we’ll just assume it was at midnight.
M-x calc t N (put the current time on the stack) '<Jul 17, 1952> (press ' to enter algebraic mode, then you input the date). - (subtract the two to get the number of days David has been alive) 24 (we're going to multiply by 24, the number of hours in a day) 60 (the number of minutes in an hour) 60 (the number of seconds in a minute) * * * Final result: 1: 1910255938.01
There you have it, he’s… wait, how many seconds? That’s really hard to read.
Back into calc!
d g (toggle digit grouping) The final final result: 1: 1,910,255,938.01
Ah, that’s a 1.9 billion seconds. Sweet!