Shulchan Aruch 285 codifies the obligation for each individual to read that week's parshah, the text twice and the (Aramaic) translation once.
In some years (e.g. this year, 5779) the parshiyot read in Israel and the Diaspora are one week out of sync for a number of weeks.
What does someone do when travelling from Israel to the Diaspora during this time? Would he have to read the parashah in the Diaspora a second time? Or maybe his reading the week before counts?
What does someone do when travelling from the Diaspora to Israel? Does he need to (at some point) read the parashah that he will miss hearing?
Does it make a difference if one knows that he will be returning home after his trip? Can he stick to his original schedule, despite being out of sync with where he is spending that shabbat?