You're right, one must be careful here. When EOD data contains a date, but no time, the timestamp is the begin of the day. But the data is from the end of the day. That's future peeking. Zorro corrects this automatically for EOD price history, but not for data imported from arbitrary files. This must be done by the user. I'll put a warning in the manual and maybe we'll provide a time offset feature on import in a future version.