shift this by the given unit
Is the given Date range a (non-strict) subset of the given range
produce a contiguous non-overlapping set of DateRanges whose union is equivalent to this.
produce a contiguous non-overlapping set of DateRanges whose union is equivalent to this. If it is passed an integral unit of time (not a DurationList), it stops at boundaries which are set by the start timezone, else break at start + k * span.
make the range wider by delta on each side.
make the range wider by delta on each side. Good to catch events which might spill over.
Extend the length by moving the end.
Extend the length by moving the end. We can keep the party going, but we can't start it earlier.
represents a closed interval of time.
TODO: This should be Range[RichDate, Duration] for an appropriate notion of Range