sehri

Q:

1. I have read that one can only miss his fast if one is a traveller at sehri time. What will be the ruling of an individual who is travelling abroad but his  light is at afternoon time (meaning he is still at home at sehri time)?

2. If that person needs to fast, how will he do Iftar because different countries have different iftar times.

3. Also, will putting Vicks under the nose and sniffing it throurg out the day break one's fast? I have read that it doesn't because it does not have a body. Will that have the same ruling if one was to sniff Vicks from a tissue (i.e. putting some vicks on a tissue and then inhaling the subtance form the tissue?

Q: On the first day of Ramadhaan I did not know about the 18 degrees fajr time so I ate suhoor after fajr entered according to 18 degrees fajr time. After the first day I found out about the 18 degrees fajr time and how its more accurate than 15 degrees so I started following that after the first day. Regarding that first day, since I did not know about the 18 degrees fajr time, do I have to make it up? And do I have to make it up immediately after Ramadhaan or any time up until the next Ramadhaan?

Q:

1) Zaid followed his faithful bedroom clock for many years and he used to complete eating his sehri at the last minute based on the time on this clock. He recently compared his clock with the BBC time and found it to be 3 minutes slow. Is he muqallaf of following this time and repeating his fasts considering the possibilty that the BBC or any other central bureau time may also be incorrect.