Is there a difference between these two expressions? Are they perfect synonyms?
"To date" implies that the current state is unchanged from the previous state, while "until now" implies that it has just changed. For instance:
Would mean the Foos have not won a game.
Would mean that they just won their first game.
Those expressions could have slightly different meanings especially when talking about finance.
Compare the statements
To date does a good job of conveying the process of tracking the progress. However, until now seems to imply that the fund's growth rate has changed, thus our second statement implicitly requires further elaboration. Besides, until now and since the start of the year don't go well together.