You can specify a delay—the time that a frame is displayed—for single frames or for multiple frames in an animation. Delay time is displayed in seconds. Fractions of a second are displayed as decimal values. For example, one-quarter of a second is specified as .25. If you set a delay on the current frame, every frame you create after that will remember and apply that delay value.
Choose a value from the pop‑up menu. (The last value used appears at the bottom of the menu.)
Choose Other, enter a value in the Set Frame Delay dialog box, and click OK. If you selected multiple frames, specifying a delay value for one frame applies the value to all frames.