Fitr: delayed moon confirmation can shift the prayer to the next day, but not further if impeded.
Adha: a communal impediment can allow the prayer on 11 or 12 Dhu al-Hijjah.
These are rules for postponing a communal prayer, not the same as an individual making up a missed congregation.
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Eid Prayers and the Takbirs of Tashriq
Fitr: delayed moon confirmation can shift the prayer to the next day, but not further if impeded.
Adha: a communal impediment can allow the prayer on 11 or 12 Dhu al-Hijjah.
These are rules for postponing a communal prayer, not the same as an individual making up a missed congregation.