Matt Johnson specializes in the subject of dates and times in computing, including time zones and daylight saving time. He is a core team member of Moment.js, the leading date-time library for JavaScript, and regularly contributes to other time-related projects including Noda-Time for .NET, and the IANA Time Zone Database. Matt is also the author of “Date and Time Fundamentals”, a 6-hour long video course available on Pluralsight. In his day job, Matt works at Microsoft on the Azure cloud platform. He also spends a lot of his time advising other groups at Microsoft on time zone concerns. You can find Matt answering Stack Overflow questions for the datetime and timezone tags, or check out his blog at You can also listen to Matt geek out about time on .NET Rocks podcast #1230 and HanselMinutes podcast #485.