983. Making Separate Eiruvs for Adjacent Days

Eiruvin 8:5

Regarding a yom tov that falls next to Shabbos - either before or after it - and the two days of yom tov observed outside of Israel, one person may make two eiruvs in opposite directions and rely one for the first day and the other for the second day. Similarly, one may make an eiruv in one direction and rely on it for one of those two days and on the other day act like all the other residents of his city who do not have an eiruv, traveling 2,000 cubits in every direction. This only applies to the two days of yom tov as observed outside of Israel. The two days of Rosh Hashana are considered as a single day and one may only make an eiruv in one direction for both days.

Eiruvin 8:6

One may likewise make an eiruv techumin with a condition like, “This eiruv will be valid for this Shabbos but not for any other,” or “This eiruv will be valid for another Shabbos but not for this Shabbos,” or “valid on Shabbos but not on yom tov,” or “valid on yom tov but not on Shabbos.”