Time + 6 hours

Hi,

I have log files that show US server time (-6) so I need to add 6 hours to the time column in my table.

I have  a "Tijd VS" column that shows the date and time (e.g. 31-8-2018 0:00:00 --> A date/time column in Power BI)

I tried to add a new measure --> Tijd = 'EZproxy log'[Tijd VS]+ TIME(06;00;00)

But I got the error: A single value for column 'Tijd VS' in table 'EZproxy log' cannot be determined. This can happen when a measure formula refers to a column that contains many values without specifying an aggregation such as min, max, count, or sum to get a single result.

Does it go wrong because I have a date/time column? I also tried the same formula with my date/time column separated in a date and a time column. In that case the +6 hours work but Power BI adds a date to it (e.g. 30-12-1899 6:00:00) which is also not correct.

What am I doing wrong? And how can I fix it?