i have a .NET Addin which access PI Trends and saves start and end Time (same behavior with VBA). I access start and End Time via the properties of a trend symbol.
When the user selects a relative start time bigger than exactly *-7d i get back absolute timestamps. The processbook show the correct relative time in the define trend window
For example User sets Starttime: *-7d / Endtime *
myTrend.Start and Endtime are exactly what the user set
For example User sets Starttime: *-8d / Endtime *
myTrend.Start: "21.01.2014 10:19:12,212" and Endtime is: "29.01.2014 10:19:12,212"
The limit seems to be exactly 7 days, no matter if specified as days, minutes etc.
How this can be avoided? how can i get relative timestamps exactly like shown in the trend definition?