The time of slaughtering the Udhiyah:

 
Slaughtering Al-Udhiyah should be in the period that starts after Eid Al-Adha prayer and ends before the sunset of the 3rd day of Eid. However, the best time for  slaughtering is the first day of Eid; after Eid Al-Adha prayer till the time before sunset of the same day. It is detestable to slaughter it at night. 

Al-Udhiyah is an animal of the an'aam class (i.e., camel, cow, sheep or goat), provided that the sheep should be 6 months old, and the goat should be 1 year old according the opinions of jurists.