now
Read the current value of the clock.
As this the clock is not monotonic, calling this function repeatedly will not necessarily produce a sequence of non-decreasing values.
The returned timestamps represent the number of seconds since 1970-01-01T00:00:00Z, also known as POSIX's Seconds Since the Epoch, also known as Unix Time.
The nanoseconds field of the output is always less than 1000000000.