What are the Sharia consequences when the sacrificial time for the uḍḥiyyah comes to an end?
All praise is due to Allah, and may peace and blessings be upon our Master, the Messenger of Allah.
If the sun sets at the end of the last of the Days of Tashrīq and the sacrificial animal (uḍḥiyyah) has not yet been slaughtered, then its prescribed time has elapsed. Should one slaughter it thereafter, it will not be considered a valid uḍḥiyyah.
However, if the sacrifice was vowed (mandhūrah), then it remains obligatory to slaughter it — and it shall be carried out as a make-up (qaḍā') of the vow, with its meat distributed in the rightful channels designated for such sacrifices.
It is stated in Bushrā al-Karīm (p. 702): "If one slaughters after the sunset of the last of the Days of Tashrīq... it isn`t considered a valid uḍḥiyyah, unless it was vowed — in which case it is carried out as qaḍā'."
And Allah Almighty knows best.
Can I start fasting based on the moon sighting of another country?
You must follow the moon sighting of the country you are in.
Does using a respiratory device (oxygen) affect the validity of fasting?
Using an oxygen device does not affect the validity of fasting because oxygen is a gas with no physical substance.
However, if medicinal substances with physical particles are added to the oxygen, its use would break the fast, as it enters the body cavity through a natural passage.
Is Zakah (obligatory charity) due on the items used in the trading process such as: cars , shops etc..?
No Zakah is due on equipments used in the trading process such as cars and the like.
