Commit c564169

Returns the number of seconds, as an integer, since a port-specific reference point

in time (for embedded boards without RTC, usually since power up or reset). If you

want to develop portable MicroPython application, you should not rely on this

function to provide higher than second precision, or on a specific reference time

point. If you need higher precision, use ``ticks_ms()`` and ``ticks_us()`` functions,

if you need calendar time, ``localtime()`` without argument is the best possibility

to get it.

.. note::

**CPython difference:** In CPython, this function returns number of

seconds since Unix epoch, 1970-01-01 00:00 UTC, as a floating-point,

usually having microsecond precision. With MicroPython, only Unix port

uses the same reference point, and if floating-point precision allows,

returns sub-second precision. Embedded hardware usually doesn't have

floating-point precision to represent both long time ranges and subsecond

precision, so use integer value with second precision. Most embedded

hardware also lacks battery-powered RTC, so returns number of seconds

since last power-up or from other relative, hardware-specific point

(e.g. reset).