offset_happens_when_timespan_starts

abjad.timespans.offset_happens_when_timespan_starts.offset_happens_when_timespan_starts(timespan=None, offset=None, hold=False)

Makes time relation indicating that offset happens when timespan starts.

>>> relation = abjad.timespans.offset_happens_when_timespan_starts()
>>> abjad.f(relation)
abjad.timespans.OffsetTimespanTimeRelation(
    inequality=abjad.timespans.CompoundInequality(
        [
            abjad.TimespanInequality('offset == timespan.start'),
            ],
        logical_operator='and',
        ),
    )

Returns time relation or boolean.