Measure your working time on windows

For measure working time on windows I wrote a little script. It calculates the time since the last login. The output of the script looks like this:

Login:        10:10
Now:          18:13
======================
Working time: 8 h 3 m

The script is written in Ruby and runs under cygwin. I saved the script in a folder tools in my homedir and have the following alias in my .bashrc:

alias wt='~/tools/workingtime.rb'

So finally the script looks like this:

#!/usr/bin/ruby
HOURS_PER_DAY = 24
MINUTES_PER_HOUR = 60
SEC_PER_MINUTE = 60 
times = []

#get times from windows systeminfo
#Systembetriebszeit:                     0 Tage, 0 Stunden, 10 Minuten, 0 Sekunden
uptime_string = `systeminfo | grep Systembetriebszeit`
uptime_string.slice!(0..28)
time_strings = uptime_string.split(',')
time_strings.each do |s|
times 

Known issues: 

The script is based on the windows command systeminfo. Systeminfo returns values in the language of the operating system. So this works only with a german windows. Replace "Systembetriebszeit" with whatever your systeminfo command returns for the uptime.

Update: Workingtime.rb moves to github. Follow the installation instructions there.