"Have a good day" is often expressed as one departs.

Here's How to Have a Better Day

Sometimes it is the things that we don't do
that make a better day:
not procrastinating
not becoming impatient
not being possessive
not being anxious to impress others
not cherishing an inflated opinion of yourself
not taking advantage of others
not keeping a record of hurts done to you
not worrying about tomorrow.

Love is patient, love is kind, and is not jealous; love does not brag and is not arrogant, does not act unbecomingly; it does not seek its own, is not provoked, does not take into account a wrong suffered, does not rejoice in unrighteousness, but rejoices with the truth; bears
all things, believes all things, hopes all things,
endures all things.
1 Corinthians 13:4-7 NASB

By avoiding these things, you will have a better day!