历久弥新

歷久彌新
lìjiǔmíxīn
  1. lit. long in existence but ever new (idiom)
  2. fig. timeless; unfading

CEDICT

to last long and become even more vigorous as time passes

Wiktionary

经过长久的时间，不但没有衰败、陈旧，反而更新、更好。

重編國語辭典

经过长久的时间，不但没有衰败、陈旧，反而更新、更好

維基詞典

Entry Composition

1 历久 lìjiǔ to last for a long time
=2 弥 mí
  1. full
  2. to fill
  3. completely
  4. more
=2 弥 mí brimming or overflowing
3 新 xīn
  1. new
  2. newly
  3. meso- (chemistry)