Spark meal plans don't say what time to eat the snacks.
There should be food suggested for the four meal groups - breakfast, lunch, dinner and snack. You can split up the snack suggestions into 2 or 3 snack breaks, or you can eat it all at one snack break. Whatever works for you.
There is no truth to that old diet adage and Spark does not endorse stopping eating at any particular time of day as a weight management strategy.