Q. What is Horav Miller’s opinion in regards to traveling back or forwards on time? Does the Torah mention this as a possibility?

A. it is common to find in regards to the Yom Tov of Shavuos the notion of being present at the time of the reading of the Torah as if we are back on the day of receiving of the Torah at Har Sinai. A similar notion is mentioned in regards to Pesach in the hagada. However, the key word “keilu” is used, meaning that it is only as if it were, a spiritual notion but not a physical reality.
Horav Shlomo Miller’s Shlit’a opinion is that we find in Halacha some sort of minimal travel back and forth in time when crossing the dateline. Real traveling back in time would seem an impossibility as you would be able to change true facts already recorded in the Torah.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a