Looking for helper or plugin to format last login date.

Hi folks.

I'm looking for a plugin or helper that takes a datetime/date/time
object and returns a string value of how long ago that was.

Examples of the kind of thing I'm looking for:

You last login was...
last week
2 weeks ago
n weeks ago

I'm sure something like this exists, I just can't seem to find it.

Your help is appreciated.

Douglas F Shearer