What you do is this:

1) Import the CSV to a dataset as you normally would, knowing that the timestamps are in the given timezone.
2) Modify the dataset using dataset functions and time functions, and the Now variable. Detect daylight savings with dst().
https://manual.zorro-project.com/data.htm
https://manual.zorro-project.com/month
https://zorro-project.com/manual/en/date.htm
3) Save your dataset to a t6 file with dataSave.