There are two ways to invoke moving the current time indicator, and that is, by clicking on the time counter in the timeline, or by pressing Cmd+G (Ctrl+G). Once the dialog box is open , there's a lot you can do with it.
Type in the time you'd like to go to. There is no need to type colons for the time. For example, you can just put 415 to move to the four and a half second mark using NTSC 29.97 fps counting.
You can move forward a relative amount from your current position; simply type an amount such as +20 to move 20 frames forward.
Conversely, you can move backward in time, but the phrasing is a little tricky. Open the Go To Time box and type in + “45 frames to move back 45 frames. While it seems confusing at first, you are saying "Add a negative adjustment to the current time."
If you want to pre-roll an effect, you need to move to a time before your composition begins. Type in negative three seconds ( “300) in the Go To Time box, your current time indicator. This way, particle effects or those that need to ˜ramp up have adequate time to begin.
Under After Effects 6.5, the Current Time field can also be scrubbed allowing you to shuttle through the timeline.