time will tell

(only) time will tell

The true meaning, result, or outcome will only be known in the future or after more time has passed. It's hard to predict how this law will really impact people's lives—only time will tell. Time will tell whether the film is truly considered a success. Some flops go on to become cult favorites.
See also: tell, time, will
Farlex Dictionary of Idioms.

(Only) time will tell.

Prov. You will only know the outcome after time has passed. Jill: Do you think Bill and Nancy will have a happy marriage? John: Only time will tell. I'm not sure yet if our advertising campaign was a success. Time will tell.
See also: tell, time, will

Time will tell.

Something will become known in the course of time. I don't know if things will improve. Time will tell. Who knows what the future will bring? Only time will tell.
See also: tell, time, will
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

time will tell

Sooner or later something will become known or be revealed, as in I don't know whether or not they'll like the reconstruction; only time will tell. This proverbial phrase dates from the early 1500s.
See also: tell, time, will
The American Heritage® Dictionary of Idioms by Christine Ammer.

(only) time will tell

the truth or correctness of something will only be established at some time in the future.
See also: tell, time, will
Farlex Partner Idioms Dictionary

time (alone) will ˈtell

,

only time will ˈtell

(saying) used to say that you will have to wait for some time to find out the result of a situation: Only time will tell if the treatment has been successful.
See also: tell, time, will
Farlex Partner Idioms Dictionary

time will tell

Wait and see. This cautionary adage was already in print in 1539 in R. Taverner’s translation of Erasmus: “Tyme discloseth all thynges.” It was certainly a cliché by the time E. H. Porter used it in Pollyanna (1913): “The doctor had looked very grave . . . and had said time alone could tell.”
See also: tell, time, will
The Dictionary of Clichés by Christine Ammer
See also:
  • (only) time will tell
  • time alone will tell
  • be level pegging
  • be anyone's/anybody's call
  • level pegging
  • it's anyone's/anybody's call
  • IYSWIM
  • you can never tell with (someone or something)
  • you never know with (someone or something)
  • take on a new significance