Time travel bug

Time travel in movies and shows is normally depicted the same way. The user enters a date or time into said time machine. The machine blinks flashes and gets hot while it begins sending the user back in time. Normally the user lands in the exact same spot the machine was originally used. This is my problem with time travel. How can the user land in the very same spot? They only entered in date/time combination. Earth's position has not been accounted for when entering the date/time information in. So if the user enters any date not in year intervals, they would likely be sent directly into space, because when the date/time was entered in thats where "that position" would have been oriented then. Make sense?