Solved: subtracting time from date/time power query

Anonymous · ‎05-06-2019

Hello

I have a table with date/time column and time column. I want to subtract the time column from the date/time column in Power Query, but I receive this message

Expression.Error: We cannot apply operator - to types DateTime and Time.
Details:
Operator=-
Left=07/04/2019 14:00:00
Right=00:00:00

i used a simple formula when using the Adding aCustom Column

=[date/time] - [time]

I know it's possible with DAX, but i need to do it within Power Query

Thanking you in advance

v-piga-msft · ‎05-14-2019

Hi @Anonymous ,

If you want to achieve your desired output with Power Query, you could refer to my code below.

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMjIwtNQ11DVVMDCyMjS1MjBQ0lEyMATSIGasDlyBIYoCA5iCWAA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [#"Date/Time" = _t, Time = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Date/Time", type datetime}, {"Time", type time}}),
    #"Added Custom" = Table.AddColumn(#"Changed Type", "Custom", each DateTime.Time([#"Date/Time"])-[Time]),
    #"Split Column by Position" = Table.SplitColumn(Table.TransformColumnTypes(#"Added Custom", {{"Custom", type text}}, "en-US"), "Custom", Splitter.SplitTextByPositions({0, 1}, false), {"Custom.1", "Custom.2"}),
    #"Removed Columns" = Table.RemoveColumns(#"Split Column by Position",{"Custom.1"}),
    #"Split Column by Delimiter" = Table.SplitColumn(Table.TransformColumnTypes(#"Removed Columns", {{"Date/Time", type text}}, "en-US"), "Date/Time", Splitter.SplitTextByDelimiter("#(tab)", QuoteStyle.Csv), {"Date/Time.1", "Date/Time.2"}),
    #"Duplicated Column" = Table.DuplicateColumn(#"Split Column by Delimiter", "Date/Time.1", "Date/Time.1 - Copy"),
    #"Split Column by Delimiter1" = Table.SplitColumn(#"Duplicated Column", "Date/Time.1 - Copy", Splitter.SplitTextByDelimiter(" ", QuoteStyle.Csv), {"Date/Time.1 - Copy.1", "Date/Time.1 - Copy.2", "Date/Time.1 - Copy.3"}),
    #"Changed Type1" = Table.TransformColumnTypes(#"Split Column by Delimiter1",{{"Date/Time.1", type datetime}, {"Date/Time.2", type text}, {"Custom.2", type time}, {"Date/Time.1 - Copy.1", type date}, {"Date/Time.1 - Copy.2", type time}, {"Date/Time.1 - Copy.3", type text}}),
    #"Removed Columns1" = Table.RemoveColumns(#"Changed Type1",{"Date/Time.2", "Date/Time.1 - Copy.2", "Date/Time.1 - Copy.3"}),
    #"Changed Type2" = Table.TransformColumnTypes(#"Removed Columns1",{{"Date/Time.1 - Copy.1", type text}, {"Custom.2", type text}}),
    #"Added Custom1" = Table.AddColumn(#"Changed Type2", "Custom", each [#"Date/Time.1 - Copy.1"]&" "&[Custom.2]),
    #"Changed Type3" = Table.TransformColumnTypes(#"Added Custom1",{{"Custom", type datetime}})
in
    #"Changed Type3"

Here is the output.

In addition, @ImkeF may have other simpler solution for your requirement.

Best Regards,

Cherry

Community Support Team _ Cherry Gao
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

View solution in original post

ImkeF · ‎05-14-2019

The key lies in not transforming the Time-column to Time, but to duration instead in the first "Changed Type"-step.

Then you can simply subtract it like so:

let 
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMjIwtNQ11DVVMDCyMjS1MjBQ0lEyMATSIGasDlyBIYoCY5iCWAA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [#"Date/Time" = _t, Time = _t]), 
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Date/Time", type datetime}, {"Time", type duration}}), 
    #"Added Custom" = Table.AddColumn(#"Changed Type", "Custom", each [#"Date/Time"]-[Time])
in
    #"Added Custom"

Imke Feldmann (The BIccountant)

If you liked my solution, please give it a thumbs up. And if I did answer your question, please mark this post as a solution. Thanks!

How to integrate M-code into your solution -- How to get your questions answered quickly -- How to provide sample data -- Check out more PBI- learning resources here -- Performance Tipps for M-queries

View solution in original post

Gordonlilj · ‎05-06-2019

Hi,

You could use the code below in a custom column and it should work

DateTime.Time([Table])

Just switch the table to your own

Anonymous · ‎05-06-2019

Thanks for your reply.

I think there was a missunderstanding.

I have two columns one with Date/Time and another with Time only. Time column is populated by 00:00:00 or 01:00:00 and I want to subtract these from the Date/Time column

Date/Time Time UTC Time

01/05/2019 02:15:00 01:00:00 01/05/2019 01:15:00

01/01/2019 02:15:00 00:00:00 01/01/2019 02:15:00

Kind regards

v-piga-msft · ‎05-14-2019