yī rì qiān lǐ 一日千里

成语 (Idiom)：一日千里 (A Thousand Mile A Day)

意思（Meaning)：

如骏马一般能一日行一千里，比喻进展很快。
Like a fine horse able to travel a thousand mile in a day,  metaphorical meaning is improvement at a tremendous pace.

例如（An example):

电脑领域里一日千里的进展, 为许多人带来了喜悦。
Using this idiom to describe the advancement of computer technology, has brought joys to many people.

典故(Classical Literature): 

《庄子·秋水》：“骐、骥、骅、骝，一日而驰千里。”《史记·刺客列传》：“臣闻骐骥盛壮之时，—日而驰千里；至其衰老；驾马先之。”