Erik’s Lab

How to calculate billable time in Ruby using epoch-seconds. Out of interest,I ported the Perl-Code to Ruby and have to say, wow. Ruby is very elegant (not sure if my code is, but it works).

The idea was to use another (scripting-)language readily available on OS X. As I said already, it works like the Perl-version:


#!/usr/bin/ruby

#output information for copying
puts "customer|topic"
puts "Start: #{starttime}"
puts ""


start_record.rb gets the current time in epoch-seconds and writes it to a file called timetemp.txt in the same directory. Nothing new here, but I like the construct timetemp.puts epochtime, Ruby is very clean.

When you’re done, end_record.rb is used to read in the starting time and to perform the necessary calculations:


#!/usr/bin/ruby

# output results
puts "Start: #{starttime}"
puts "End: #{endtime}"
puts "Seconds: #{timesecs}"
puts "Minutes: #{timeminutes}"
puts "Hours: #{timehours}"
puts ""
puts "Bill: "
puts ""


If you don’t want to copy and paste from the terminal-window, simply pipe the results to a file like this:

$ > ruby start_record.rb > my_file.txt

and when you’re done

$ > ruby end_record.rb >> my_file.txt

Remember though, > means overwrite the file if it exists. If you want to append, use >>. This might be obvious to most people fluent in UNIX, but should be noted as a “just in case you need to know”.

Technorati Tags: Ruby, epoch-seconds, calculating with epoch-seconds, OS X, Linux

Every freelancer uses some kind of accounting-package to keep track of the billable time, but, given multiple machines, on-site gigs and the like, keeping track is not always that easy, isn’t it? For that reason, I came up with a really simple combination of two Perl-scripts.

The first one, start_record.pl, writes the epoch-seconds to a temporary file and prints some information to the terminal-window.

Update: Thanks to Hebikai for pointing out a problem with the relative path, the scripts are using the environment-variable $HOME to determine the path now.


#!/usr/bin/perl

open(MY_HANDLE, ">$DATA_dir/time.log") or die "$0: something went wrong: $!\n";
print MY_HANDLE $start_time."\n";
close(MY_HANDLE);


The script assumes, that there is a directory called time_control_stuff in ~/work/. Its output should be copied or piped into a file, it records the time you started. If you want, feel free to modify the customer|topic and Remarks lines to taste.

If you are done with the task, the end_record.pl script comes into play.


#!/usr/bin/perl
$HOME_dir = $ENV{HOME};
$DATA_dir = "$HOME_dir/work/time_control_stuff";
$end_time = time;

print "Total: ".$total_time."\n";
print "Mins: $total_mins\n";
print "Hours: $total_hours\n";
print "\nBill: \n\n";


Its output is pretty much self-explanatory, copy or append to the same file and you are done.

I use an USB-stick to carry the scripts with me all the time. If I need to record billable time and don’t have access to one of my machines, these scripts are my way to go. I input the recorded data into my accounting-package as soon as I’m able to do so.

Granted, they could be a lot more sophisticated, but remember KISS (Keep It Simple S…) rules. Use the scripts as a starting-point for you “accounting on the road.”