A young man approached me one night and asked me what the halacha is when he put on his tefillin earlier that day about 25 minutes after sunset. The Kotzker in me had one response:-).
Instead, I told him that according to Rabbeinu Tam - he is A.O.K. He flashed a winning smile and thanked me.
Baruch Hashem for shittas Rabbeinu Tam - whatever the pshat may be [we touched upon this not long ago on these pages].