Change the snap resolution
You can specify the intervals on the timeline at which you can set keyframes. This interval rate is called snap resolution because it refers to where on the timeline the play head can be snapped. For example, if you change the snap resolution to 10 frames per second, you could set keyframes at every tenth of a second along the timeline. Snap resolution also affects how the Playback controls navigate through frames.
Timeline snapping does not apply to the frame rate or to the speed of your animation when your application runs.
For more information, see "Frame rates" in the topic Animating objects.
Select the timeline by clicking Open a Storyboard in the Objects and Timeline panel and then selecting a storyboard.
Click Snapping options .
The Snapping Options dialog box appears.
In the Snap resolution per second text box, type a value that the playhead should snap to when navigating through frames and setting keyframes.
Make sure snapping is turned on.
For more information, see Turn timeline snapping on or off.