Looking to subtract time from a date.Time column in Power Query

[m_roussakis]

I have this formula :

new column = if [EVT_CD] = "TF" then [EVT_TMSTMP] - #duration(0, 1, 0) else [EVT_TMSTMP]

but it gives me an error in new column.

My [EVT_TMSTMP] column is in Date/Time format, and looks like this:

Can anyone fix my formula so I dont get an error when a TF record is found?

[m_roussakis · Accepted solution]

Your mention of requiring 4 parameters jogged my memory and i was able to fix this. Thanks!

= if [EVT_CD] = "TF" then [EVT_TMSTMP] - #duration(0, 0, 1, 0) else [EVT_TMSTMP]

[HotChilli]

Please, if you get an error and want help you really have to post the error message.  Also, Duration takes 4 parameters