time manual page - Built-In Commands

## Tcl8.6.16/Tk8.6.16 Documentation > Tcl Commands, version 8.6.16 > time

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### NAME

time — Time the execution of a script

### SYNOPSIS

time script ?count?

### DESCRIPTION

This command will call the Tcl interpreter count times to evaluate script (or once if count is not specified). It will then return a string of the form

    503.2 microseconds per iteration

which indicates the average amount of time required per iteration, in microseconds. Time is measured in elapsed time, not CPU time.

### EXAMPLE

Estimate how long it takes for a simple Tcl for loop to count to a thousand:

    time {
        for {set i 0} {$i<1000} {incr i} {
            # empty body
        }
    }

### SEE ALSO

clock

### KEYWORDS

script, time
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