Either use a script like this
Option Explicit
data.Root.Clear
dim chObj : set chObj = data.root.ChannelGroups.Add("group").Channels.Add("time",DataTypeChnDate)
chObj.Values(1) = CDate("03/16/2015 17:18:31")
dim chNr : chNr = chObj.Properties("number").Value
dim offsetInSeconds : offsetInSeconds = 8 * 60 * 60
Call ChnOffset(chNr,chNr,"free offset")
or use
Analysis.Basic Mathematics.Offset Corrections
and add offset in seconds as "Add any offset"