朝三暮四

zhāosānmùsì
  1. lit. say three in the morning but four in the evening (idiom); to change sth that is already settled upon
  2. indecisive
  3. to blow hot and cold

CEDICT

Entry Composition

1 朝 zhāo morning
2 三 sān
  1. three
  2. 3
3 暮 mù
  1. evening
  2. sunset
4 四 sì
  1. four
  2. 4