Power Query M filter data by Dynamic Date (PQ not DAX) Start of Month

You're welcome DavidMoss

As a matter of fact I just copied the DateTimeZone.FixedUtcNow() function from the example, which - in my opinion - doesn't mean that time zones are taken into account.

Actually I spent some time on the subject of converting international times and I even created a function to convert a date/time from one Windows time zone to the date/time in any other Windows time zone in the period 2000 through 2027.

As a basis, I created about 130 files (1 for each Windows time zone) with all date/times on which the clock was adjusted in that Windows time zone, typically DST (Daylight Saving Time) switches, with UTC-date/time and corresponding local date/time directly after the switch. During creation I had to adjust the Windows time zone on my computer about 130 times...

This would be closest to a reliable conversion, but then again it should be noted that any historic date/time conversions (e.g. before 2007), become very unreliable as not all historic information is available in Windows, and any future date/times may be subject to government decisions.

Microsoft tries to keep up the pace with developments, https://blogs.technet.microsoft.com/dst2007/ but sometimes decisions are taken on short notice and still not everything is accounted for, like temporary DST suspensions in some Islamitic countries during Ramadan.

As a last remark: a specific point of attention with DST switches are missing times (when clocks are moved forward) and ambiguous times (when clocks are moved back).

Maybe too much information but I understood this would be an informative topic. :smileylol: