time – time related functions

The time module provides functions for getting the current time and date, and for sleeping.

Functions

time.localtime([secs])

Convert a time expressed in seconds since Jan 1, 2000 into an 8-tuple which contains: (year, month, mday, hour, minute, second, weekday, yearday) If secs is not provided or None, then the current time from the RTC is used. year includes the century (for example 2014).

  • month is 1-12
  • mday is 1-31
  • hour is 0-23
  • minute is 0-59
  • second is 0-59
  • weekday is 0-6 for Mon-Sun
  • yearday is 1-366
time.mktime()

This is inverse function of localtime. It’s argument is a full 8-tuple which expresses a time as per localtime. It returns an integer which is the number of seconds since Jan 1, 2000.

time.sleep(seconds)

Sleep for the given number of seconds. Seconds can be a floating-point number to sleep for a fractional number of seconds.

time.sleep_ms(ms)

Delay for given number of milliseconds, should be positive or 0.

time.sleep_us(us)

Delay for given number of microseconds, should be positive or 0

time.ticks_ms()

Returns an increasing millisecond counter with arbitrary reference point, that wraps after some (unspecified) value. The value should be treated as opaque, suitable for use only with ticks_diff().

time.ticks_us()

Just like ticks_ms above, but in microseconds.

time.ticks_cpu()

Similar to ticks_ms and ticks_us, but with higher resolution (usually CPU clocks).

time.ticks_diff(old, new)

Measure period between consecutive calls to ticks_ms(), ticks_us(), or ticks_cpu(). The value returned by these functions may wrap around at any time, so directly subtracting them is not supported. ticks_diff() should be used instead. “old” value should actually precede “new” value in time, or result is undefined. This function should not be used to measure arbitrarily long periods of time (because ticks_*() functions wrap around and usually would have short period). The expected usage pattern is implementing event polling with timeout:

# Wait for GPIO pin to be asserted, but at most 500us
start = time.ticks_us()
while pin.value() == 0:
    if time.ticks_diff(start, time.ticks_us()) > 500:
        raise TimeoutError
time.time()

Returns the number of seconds, as an integer, since 1/1/2000.