How To Determine if You're In Daylight Saving Time?

I’m showing times on RESTXQ generated pages that need to be adjusted for a particular time zone. Doing the time zone adjustment is easy enough but I realized that knowing whether or not a given time zone should be standard or daylight time is a challenge not directly addressed by the XQuery time functions. So my question: does anyone have a technique for determining if a given time zone or region is using DST? Of course I can hard-code some sort of DST calendar for the time zones I know I need (U.S. time zones, European Central Time, India Standard Time) but it seemed like there ought to be a more general solution somewhere. My server is running on Linux but is developed and tested on macOS. Thanks, Eliot _____________________________________________ Eliot Kimber Sr Staff Content Engineer O: 512 554 9368 M: 512 554 9368 servicenow.com<https://www.servicenow.com> LinkedIn<https://www.linkedin.com/company/servicenow> | Twitter<https://twitter.com/servicenow> | YouTube<https://www.youtube.com/user/servicenowinc> | Facebook<https://www.facebook.com/servicenow>

Is currently using? The transition dates are in at least some cases political, and set by parliaments or whatever each year.

You could run the system command, e.g. LC_TIME="fc_CA.UTF-8" date which here returns mar 28 jun 2022 17:38:41 EDT but that depends on having the locale installed and up to date. We also don't have in XQuery or XSLT or Xpath a way to interpret "The thurd sunday in March" which is when, for example, Cuba switches. I'm not sure if tehre's a machine-readable definitive list somewhere but seems possible...