One has to see the local sighting of moon, fasting on eid day is haram.

one of my uncle who is staying as a join family with his brothers, is fasting in day of eid of local region and not participating in the feast of other brothers, saying that he is following universal moonsighting and it doesn’t harm him. Though He hasn’t fasted any voluntary fasting other days.Is it haram?does he need to be advised Or to leave it as difference of opinion?

Fasting | August 1, 2015 9:10 pm
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I know there’s no sin if someone deliberately breaks a voluntary fast but is there any sin on someone who is making up his obligatory fast after Ramadan and he deliberately breaks it?
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Actually, before I broke my fast, i have the thoughts that i am worshipping my desires and wife if i broke my fast and have intercourse with her yet i still went ahead and do it. If i repented but did not even try to fast back 14 months of 7 days that i purposely skipped and die this way. Will my sins be forgiven? If not, is it shirk or sins of breaking fast?