Forum Discussion
Convert Date/Time in UTC to Local Time with Daylight savings
- 7 years ago
Hi Anonymous ,
I think there are many ways, for example I tried to find a pattern in order to catch the November first Sunday or March second Sunday, and for your specific needs, maybe this custom function could work:
(datetimecolumn as datetime) => let date = DateTime.Date(datetimecolumn), time = DateTime.Time(datetimecolumn), firstSundayOfNovember = Date.StartOfWeek(#date(Date.Year(date), 11, 7), Day.Sunday), SecondSundayOfMarch = Date.StartOfWeek(#date(Date.Year(date), 3, 14), Day.Sunday), isSummerTime = (date = SecondSundayOfMarch and time >= #time(1,0,0)) or (date > SecondSundayOfMarch and date < firstSundayOfNovember) or (date = firstSundayOfNovember and time >= #time(1,0,0)), timeZone = (7 - Number.From(isSummerTime))*-1, MDT = DateTime.From(date) + #duration(0,Time.Hour(time),Time.Minute(time),Time.Second(time)) + #duration(0, timeZone, 0, 0) in MDT
So for dates from March Second Sunday at 1:00am until November First Sunday at 12:59:59am you will get your datetime - 6 hours and for dates from November First Sunday 1:00am until March Second Sunday at 12:59:59am you will get your datetime - 7 hoursAccording to Saint Google, the time is changed after 1:00am if you need it to be changed after 12:00am instead just remove first and last condition from isSummerTime
If you have any question or if you find any error on the code, just let me know.
Regards,
Gian Carlo Poggi
- 7 years ago
Sure Anonymous ,
Right click on Queries pane and add a new Blank Query:
Then right click on this new query and select Advanced Editor:
In this new window erase all, paste the my code and click DONE:
Now that query was converted into a function, you can rename it if you like, for example to "UTC_to_MDT":
Then in order to use this function in your table you have different options, one option is going to your query or table, then click on Add Column / Invoke Custom Function, then put a name to this new column, select your function (in my case UTC_to_MDT) and select the column from your table you need to apply this function to (in my case "Date"):
And then you will see the new date added :
Hope this helps.
Regards,
Gian Carlo Poggi
Can you please post the M language for Australian Eastern time ?
Is your source time coming in UTC? If so, try my simplified m query I posted on 05/12/21, which I have pasted below.
Please let me know if that solves your issue.
--------------------------
(datetimecolumn as nullable datetime) =>
let
DateTimeAddZone = DateTime.AddZone( datetimecolumn, 0 ),
DateTimetoLocal = DateTimeZone.ToLocal( DateTimeAddZone ),
DateTimeRemoveZone = DateTimeZone.RemoveZone( DateTimetoLocal ),
UTC_To_Local = DateTimeRemoveZone
// UTC_To_Local = DateTimeZone.RemoveZone( DateTimeZone.ToLocal(DateTime.AddZone( datetimecolumn, 0 )))
in
UTC_To_Local
- jtao5 years ago
Helper I
Thanks. Source time is in UTC. Have you tested to publish to PowerBI services ? I have used ToLocal and worked perfectly using PowerBI desktop. Once it was published in PowerBI services, no longer working.
Comments in other article :
ToLocal works great as long as users are in Power BI Desktop in Pacific Time. However, as soon as the model publishes to the Power BI Service, and the data refreshes, the date-times are no longer be Pacific Time. ToLocal() converts to the local time of the Power BI servers which are set for Universal Coordinated Time.
- freshwave5 years ago
Helper I
No, I am only using the desktop version right now with this specific mongodb database. That sucks, though now reading this and other articles, I do think I recall having seen this mentioned before.
I have been googling to try and find a good answer. The best I was able to do was tweak the response the person posted for the NZD with DST. I used the guidance of the page https://info.australia.gov.au/about-australia/facts-and-figures/time-zones-and-daylight-saving to determine what days for it to switch the DST periods, which meant changing it from the last Sunday in September, to the first Sunday in October.
I am not 100% the logic in the isSummerTime is correct, as it seems to be looking at the time based upon UTC, though your 2AM would be actually be the UTC equivalent of previous day 3PM or 4PM.
Please play and test that portion, as it may need to be tweaked.
------------------------------------------------------------------------------------------------------
(datetimecolumn as datetime) =>
let
date = DateTime.Date(datetimecolumn),
time = DateTime.Time(datetimecolumn),firstSundayOfOctober = Date.StartOfWeek(#date(Date.Year(date), 10, 7), Day.Sunday),
firstSundayOfApril = Date.StartOfWeek(#date(Date.Year(date), 4, 7), Day.Sunday),isSummerTime =
(date = firstSundayOfOctober and time >= #time(2,0,0))
or
(date > firstSundayOfOctober)
or
(date < firstSundayOfApril)
or
(date = firstSundayOfApril and time >= #time(3,0,0)),timeZone = 10 + Number.From(isSummerTime),
AST =
DateTime.From(datetimecolumn) + #duration(0, timeZone, 0, 0)
in
AST- jtao5 years ago
Helper I
Thank you. I will test it out.
Every year, the first Sunday of those months are different dates. Does it mean I need to update this M language every year for firstSundayOfOctober and first SundayOfApril ?