一日不如一日

yīrìbùrúyīrì
to be getting worse by the day

CEDICT

Entry Composition

1 一日 yīrì
  1. (literary or dialectal) one day
  2. (literary) another day in the future
  3. (literary) yesterday
  4. another day in the future
  5. one day
  6. yesterday
2 不如 bùrú
  1. not equal to; not as good as; inferior to
  2. it would be better to
3 一日 yīrì
  1. (literary or dialectal) one day
  2. (literary) another day in the future
  3. (literary) yesterday
  4. another day in the future
  5. one day
  6. yesterday