// Time interval where the cached offset is valid.
start: 0, end: -1,
// Size of next interval expansion.
- increment: 0
+ increment: 0,
+ initial_increment: 19 * msPerDay
};
// NOTE: The implementation relies on the fact that no time zones have
-// more than one daylight savings offset change per month.
+// more than one daylight savings offset change per 19 days.
+//
+// In Egypt in 2010 they decided to suspend DST during Ramadan. This
+// led to a short interval where DST is in effect from September 10 to
+// September 30.
+//
// If this function is called with NaN it returns NaN.
function DaylightSavingsOffset(t) {
// Load the cache object from the builtins object.
// the offset in the cache, we grow the cached time interval
// and return the offset.
cache.end = new_end;
- cache.increment = msPerMonth;
+ cache.increment = cache.initial_increment;
return end_offset;
} else {
var offset = %DateDaylightSavingsOffset(EquivalentTime(t));
// the interval to reflect this and reset the increment.
cache.start = t;
cache.end = new_end;
- cache.increment = msPerMonth;
+ cache.increment = cache.initial_increment;
} else {
// The interval contains a DST offset change and the given time is
// before it. Adjust the increment to avoid a linear search for
var offset = %DateDaylightSavingsOffset(EquivalentTime(t));
cache.offset = offset;
cache.start = cache.end = t;
- cache.increment = msPerMonth;
+ cache.increment = cache.initial_increment;
return offset;
}