That happy day will be for ever embedded in my memory.

那个幸福的日子将永远留在我的记忆中。

youdao

A knock at the door dispelled Sarah's visions of that happy day.

一声敲门声驱散了莎拉对快乐日子的想像。

youdao

I wasn't feeling especially happy that day.

那天我并不十分高兴。

《牛津词典》

It was a tradition to open the White House on that day so the president could wish visitors a happy new year.

VOA: special.2009.10.08

Paul felt truly happy for the first time that day.

VOA: special.2009.04.04

A Happy Meal that includes a cheeseburger,French fries, and a soda contains half a day's worth of calories and saturated fat, along with nearly a day's worth of sodium, and two day's worth of sugar.

VOA: standard.2010.06.24

Obama at town-hall meetings appears engaged but not fervently so, as if there were several other things that he would be equally happy doing that day.

NEWYORKER: The Conciliator

The doctor who delivered is actually one of our best friends, but she was there about 10 minutes. (Laughter.) And the nurse was there the whole time tending to this new family of ours. (Applause.) That was a happy day.

WHITEHOUSE: Strengthening Our Health Care Workforce

Still, I decided to go, and was happy to see that departure day dawned bright and sunny.

WSJ: Merrill Markoe on a Dark and Lonely Road Trip | Traveler's Tale