/// <summary>
/// Gets the inclusive upper limit of time that this rule set applies to.
/// </summary>
/// <param name="savings">The daylight savings value during the final zone interval.</param>
/// <returns>The <see cref="LocalInstant"/> of the upper limit for this rule set.</returns>
internal Instant GetUpperLimit(Offset savings)
{
if (IsInfinite)
{
return(Instant.AfterMaxValue);
}
var localInstant = upperYearOffset.GetOccurrenceForYear(upperYear);
var offset = upperYearOffset.GetRuleOffset(StandardOffset, savings);
return(localInstant.SafeMinus(offset));
}