5 hours of training in one night? All in what is presumably a totally new flying environment to you?
Just a little optimistic I'd venture.
Incidentally for private purposes anyhow, (civvie test flying is never done in the dark anyhow) I do increasingly wonder why I ever did mine, virtually no UK airfields ever open at night except for night training, which rather defeats the point to my mind. Mine gets used occasionally, but never with pax since I never manage to get the night take-offs and landings in that would allow it.
G