Double-tap or two single-taps?

Question

What is the time limit for two taps to be considered a double-tap, on the iPhone OS?

// Edit: Why is this important?

In order to handle single-tap and double-tap

Answer 1

On Developer Forums on developer.apple.com, an Apple developer said:

• There's no constant time interval, but the system-wide definition is implicit today in the tapCount property of UITouch.
• There is not default value for this delay and for touch-and-hold delay.
• SpringBoard has the value hardcoded.

I have submitted this to Apple as bug 68405.