Chinese
 | 
 one; 1; single 
one; 1; single; a; (before verbs) as soon as, once; (before a noun) entire (family, etc.) 
  | 
day; sky; heaven | 
simp. and trad. (一天)
 | 
 一
 | 
 天
 | 
Noun
一天 
-  one day (twenty-four hours)
 
-  the entire daytime of one day
-  幹了一天 / 干了一天  ―  gàn le yītiān  ―  worked for a whole day
 
 
-  someday; one day
-  總有一天 / 总有一天  ―  zǒng yǒu yītiān  ―  there will be a day (when ...)
 
 
-  (colloquial) the whole day
 
 
Japanese
Noun
一天 (hiragana いってん, romaji itten)
-  the whole sky; firmament