rkolter said:
But what could be the problems with the physics of this? Now that's more interesting (and it's the Science Fiction forum, so...)
1 - You have to realize you are moving through time and somehow retaining a relative position in space. The Earth is revolving around the sun at a speed of some 30 km/s. So if you slipped an hour back in time and kept your absolute position, you would be a little over 100,000 km away from the Earth. That's probably sub-optimal. How does a timeslip (natural or otherwise) keep you at a relative location?
Just as an intellectual exercise: There is no absolute reference to space, so there is nothing for you to maintain "absolute position" with respect to. So it is a bit meaningless to say that you remain in the same spot while the Earth hasn't. In order for this to have any chance of making any sense at all, you would need some type of physical "anchor" that your position is tied to in both times. If it the non-rotating inertial Earth centered frame, then as mentioned earlier, you would still need to account for Earth rotation.
But let's say that for the sake of argument, this anchor is the body of the Earth itself. That way, you would appear at the same point relative to the Earth's surface after your trip through time. This isn't the end of your problems. You solved the relative position problem, but not the relative velocity one. While it doesn't feel like it, due to the rotation of the Earth, you are changing the direction of you motion over 360° every 24 hrs. This means that right now you are moving in a direction 90° to what you were 6 hr ago or what you will be 6 hr from now. If you were to "time slip" forward by 6 hrs, while maintaining your relative position with respect to the surface
of the Earth, your momentum from your departure time will be at 90° to the direction the Earth's surface at the arrival time. You would find yourself traveling at ~1414 mph at a 45° angle to the ground If you were at the equator and some smaller speed North or South. ( if you go 6 hr into the past, you would find your self being slammed into the ground at this angle and speed.)
A slip of 23 hrs 58 min and 4 sec ( one sidereal day) would have you arriving moving in the same direction and speed as the surface in terms of the Earth's rotation, But the Earth itself is traveling in circular motion meaning in this time, it has changed it direction of motion by ~1°, and you would still find yourself moving at some 1178 mph relative to the Earth's surface.
A time slip of 1 sidereal year later would give you the same departure and arrival velocity with respect to the Earth. However exactly 1 sidereal year later is not exactly an even number of sidereal days later, so you would be dealing with a difference in velocity due to the Earth's rotation again (by ~90°)
There are two possible solutions to this.
Limit time slips to jumps between eras that separated by a time period equal to that in which both an even number of sidereal day and sidereal years fit ( A slip of 62 years puts you close enough that the velocity speed difference is pretty small).
Or try to arrange it so that the combined velocity vectors of Orbital motion and rotation add up to be the same at departure and arrival ( not easy considering that the Earth does not rotate and orbit in the same plane.)
Of course, nothing said here assumes that such time are real in any way, But it might be fun to work it into a story involving these concepts. (Of course, this would also require somehow explaining all this to the reader without boring them with a ton of exposition.)