The phrase "enlightening day" is correct and usable in written English. You could use it to describe a day during which you had a particularly meaningful or eye-opening experience. For example: "I had an enlightening day at the museum."
It was an endearing and enlightening day on the life of Kenneth Arrow.
The enlightening day featured six research presentations, two panel discussions, and a keynote by Morgan Downey, CEO of financial data technology company Money.net.net
It was an enlightening day, she said, but also depressing.
It was an enlightening day today.
Yet even the Observer, Britain's most venerable and enlightened Sunday newspaper, now has a horoscope page.
Everything, everyday is a surprise and you will never know what is going to happen next, the people you will encounter and who will help you unconditionally, giving you a smile and enlightening your day.
A discussion of this and the fumbling issues with the Giants' running backs might have been enlightening after Thursday's ball-protection drills, but it was impossible because they have decreed they shall be interviewed only on Wednesdays.
She enlightens their day, and tells them something funny and does exams.
Always good at remembering to lighten up while enlightening up, one day His Holiness even demonstrated a small Tibetan yoga and energetic breathing exercise, usually done at the outset of meditation sessions, involving throwing the arms out and to the left and right.
As Rajika Puri observed in her enlightening introductory remarks, Thursday was also Indian Independence Day, the anniversary of the creation of the Republic of India in 1947.
The day was enlightening in many respects.
Thanks to Ludwig my first paper got accepted! The editor wrote me that my manuscript was well-written
Listya Utami K.
PhD Student in Biology, Bandung Institute of Technology, Indonesia