This is a popular song originally written in Spanish in 1934 (source), having a variety of versions and covers, from Dinah Washington and Esther Philips to Barry Manilow and Rod Stewart.
It was even used for the HSBC’s mortgage advert in 2015.

Lyrics

What a diff’rence a day made
Twenty-four little hours
Brought the sun and the flowers
Where there used to be rain
My yesterday was blue, dear
Today I’m part of you, dear
My lonely nights are through, dear
Since you said you were mine
Lord what a diff’rence a day makes
There’s a rainbow before me
Skies above can’t be stormy
Since that moment of bliss, that thrilling kiss
It’s heaven when you, find romance on your menu
What a diff’rence a day made
And the difference is you.