Think about it, it'd be a great concept. Though it has been used twice already, OoT and MM, it would be awesome to just focus on timetravelling overall through a whole Zelda game. In OoT, you went back and forth time 14 years to play as young and adult Link to solve certain puzzles. In MM, you went back in time just to replay the three days given to you.

Link having an item that allows him to timetravel back and forth in time, in the same place he's using the item, instead of going to a temple (OoT: Temple of Time) to be able to do it. We'd be solving puzzles by changing the past and altering the future as we play, and everything we do in the past will have effect on the future. Small or big effects, depends on what you do to mess things up. It'd be challenging, it'd require alot of logical thinking and alot of fun gameplay. We'd be able to choose what time (limits of course, going into the future a thousand years would be overkill) to travel to.

I don't know, just a thought I had and I wanted to share it. Awesome stuff.