Tis the season, and to get into the festive spirit I’m contributing to the 2015 F# Advent calendar. Recently I was working with a client who had a need to do some business processes on at certain times. So how do you know what the time is? We crack out System.DateTimeOffset don’t we! Well it turn out that there is a flaw when it comes to using that in the form of clock drift, that think when your microwave and phone ar no longer showing the same time, even though you are sure you set it to the same time the other day!