Use Flow to get the running User’s Time Zone offset from GMT

A couple of years ago, I created a component to convert a Date value to a Datetime value in a Flow. Recently, Andy Engin Utkan, figured out a way to use this component to overcome issues he was having when using a Display Text component in a Flow when trying to show Datetime values and have them display in the correct time zone.

You are unable to use a formula in Salesforce to determine a User’s time zone. Admins have created very complex formulas trying to calculate an offset based on the User’s State or Country but then they ran into issues trying to handle Daylight Savings Time adjustments as well.

Here’s an example presented by Eric Praud on Jen Lee’s “How I Solved This” Admin Podcast where he created a new custom object, added 9 custom fields to the User object and came up with this formula to get the hour of the day when converted to the User’s local time:

IF( OR(
ISBLANK( $User.Summertime_Start_Offset__c ),

CreatedDate< DATETIMEVALUE(DATE(YEAR(DATEVALUE(CreatedDate)),MONTH($User.Summertime_Start_Date__c),DAY($User.Summertime_Start_Date__c))
-(WEEKDAY(DATE(YEAR(DATEVALUE(CreatedDate)),MONTH($User.Summertime_Start_Date__c),DAY($User.Summertime_Start_Date__c)))-1)) + $User.Summertime_Start_Offset__c /24,

CreatedDate>=
DATETIMEVALUE(DATE(YEAR(DATEVALUE(CreatedDate)),MONTH($User.Wintertime_start_Date__c),DAY($User.Wintertime_start_Date__c))
-(WEEKDAY(DATE(YEAR(DATEVALUE(CreatedDate)),MONTH($User.Wintertime_start_Date__c),DAY($User.Wintertime_start_Date__c)))-1))+$User.Wintertime_Start_Offset__c/24

),

HOUR(TIMEVALUE(CreatedDate+$User.GMT_Offset__c /24))
+IF( AND($User.Southern_Hemisphere__c, NOT(ISBLANK( $User.Summertime_Start_Offset__c ))),1,0)
-IF(HOUR(TIMEVALUE(CreatedDate+ $User.GMT_Offset__c /24))
+IF( AND($User.Southern_Hemisphere__c, NOT(ISBLANK( $User.Summertime_Start_Offset__c ))),1,0)>23,24,0)

,
HOUR(TIMEVALUE(CreatedDate+(1+ $User.GMT_Offset__c )/24))
-IF( AND($User.Southern_Hemisphere__c, NOT(ISBLANK( $User.Summertime_Start_Offset__c ))),1,0)
-IF(HOUR(TIMEVALUE(CreatedDate+(1+ $User.GMT_Offset__c )/24))
-IF( AND($User.Southern_Hemisphere__c, NOT(ISBLANK( $User.Summertime_Start_Offset__c ))),1,0)>23,24,0)

)

Andy figured out that taking the difference between the Datetime returned by my component (midnight GMT) and the Datetime returned by the Flow formula DATETIMEVALUE(Date) you would get the GMT Offset for that date based on the running User’s time zone.

Here’s a sample sub-flow I created that you could use to get the User’s GMT Offset for any date. You can call this sub-flow anywhere you need to get the offset to use in Datetime value calculations for the User’s time zone.

A Date Variable is created for Input and a Number Variable is created for Output.

A Formula is used to assign a default value of Today if no date value is passed into the flow.

The result of the fDate formula is passed into the Convert Date to Datetime Flow Action

And finally, the difference between the two Datetime values is calculated, converted to hours and passed back to the calling Flow.

Here’s an example of how you could call this sub-flow from your flow.

Depending on the date, the difference between GMT (Greenwich Mean Time) also known as UTC (Coordinated Universal Time) and the User’s time could be different.

For Example:

From the second Sunday of March at 07:00 UTC until the last Sunday of March at 01:00 UTC, London is four hours ahead of New York.
From the last Sunday of March at 01:00 UTC until the last Sunday of October at 01:00 UTC, London is five hours ahead of New York.
From the last Sunday of October at 01:00 UTC until the first Sunday of November at 06:00 UTC, London is four hours ahead of New York.
From the first Sunday of November at 06:00 UTC until the second Sunday of March at 07:00 UTC, London is five hours ahead of New York.

So, for me in the Eastern Time Zone, running the Flow with a Date of 3/1/2022 returns a value of -5 for my offset from GMT.

However, because of Daylight Savings Time, running the Flow with a date of 3/15/2022 returns the correct GMT offset of -4 for that date.

Get the Convert Date to Datetime Flow Action on UnofficialSF.
https://unofficialsf.com/convert-date-to-datetime-flow-action/

Find more from Eric Smith on his blog.
https://ericsplayground.wordpress.com/

Find out more from Andy Engin Utkan on his blog.
https://salesforcebreak.com/

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