If you go to surveyor and go to "World", it will show a clock like circle showing what time of the day you are viewing. Near the top there will be a button that says "Diurnal Cycle". If the stick in the middle of the circle is moving slowly clockwise, click the button or, if that won't work, try clicking on the stick in the circle and move it around the circle clockwise or counter clockwise. It should freeze. Then try exiting out of "World" settings tab and test your route. The time of day should stay the same.
You can also open this (Set Driver Conditions Rule) and enable it. With this, you can, while in driver, set your time of day, weather conditions, etc. while driving your train. I use this and love it.