See Mtime.span.

zero is a span of 0ns.

one is a span of 1ns.

min_span is zero.

max_span is 2⁶⁴-1ns.

equal span span' is true iff span and span' are equal.

compare span span' orders spans by increasing duration.

is_shorter span ~than is true iff span lasts less than than.

is_longer span ~than is true iff span lasts more than than.

add span span' is span + span'.

Warning. Rolls over on overflow.

abs_diff span span' is the absolute difference between span and span'.

n * dur is n times duration dur.

Warning. Does not check for overflow or that n is positive.

ns is a nanosecond duration, 1·10^-9s.

• since 1.4.0

us is a microsecond duration, 1·10^-6s.

• since 1.4.0

ms is a millisecond duration, 1·10^-3s.

• since 1.4.0

s is a second duration, 1s.

• since 1.4.0

min is a minute duration, 60s.

• since 1.4.0

hour is an hour duration, 3600s.

• since 1.4.0

day is a day duration, 86'400s.

• since 1.4.0

year is a Julian year duration (365.25 days), 31'557'600s.

to_uint64_ns span is span as an unsigned 64-bit integer nanosecond span.

of_uint64_ns u is the unsigned 64-bit integer nanosecond span u as a span.

of_float_ns f is the positive floating point nanosecond span f as a span. This is None if f is negative, non finite, or larger or equal than 2⁵³ (~104 days, the largest exact floating point integer).

• since 2.0.0

to_float_ns s is span as a nanosecond floating point span. Note that if s is larger than 2⁵³ (~104 days, the largest exact floating point integer) the result is an approximation and will not round trip with of_float_ns.

• since 2.0.0

pp formats spans according to their magnitude using SI prefixes on seconds and accepted non-SI units. Years are counted in Julian years (365.25 SI-accepted days) as defined by the International Astronomical Union.

Rounds towards positive infinity, i.e. over approximates, no duration is formatted shorter than it is.

The output is UTF-8 encoded, it uses U+03BC for µs (10^-6s).

dump ppf span formats an unspecified raw representation of span on ppf.