They refused to settle for a promise of jam tomorrow.

他们并不满足于那些美好未来的空话。

《牛津词典》

Jam tomorrow and jam yesterday — But never jam today.

明日有果酱，昨日有果酱——但是今日没有果酱。

youdao

We hope the car he promised to buy is not a jam tomorrow.

明天我希望他答应买的车不是一瓶果酱。

youdao

But he brought with him an awful lot of jam tomorrow as well as accountability today.

BBC: Pocket money and paper rounds

Cynics mutter that this is just a variant of jam tomorrow, but for the moment no one really knows.

ECONOMIST: The trouble with free trade

"Let's have some jam today for those who will look after you tomorrow, " he told delegates to rapturous applause.

BBC: 'Dinosaurs' savage New Labour