If I wanted to figure out the gravitational time dilation at different points in a the field around earth, could I just use v=gt. and find the speed that I would be moving if I went into free-fall from point x to point y. To figure out the time difference between x and y? and the t in v=gt would be the time in my free-fall frame. Then once I knew v , I could use the standard time dilation equation from SR.