We can make the future continuous in two ways:
1- Will be doing - "I will be waiting outside the station for you to arrive".
2 - Be going to be doing - "I am going to be waiting outside the station for you to arrive."
Both of these expressions have the same meaning and are interchangeable.The only difference is that will shows that a future plan was made at the time of speaking. Be going to shows that a decision about the future had already been made.
They both show what will be happening at a time in the future. It does not tell us a starting or finishing time.
Let's take a look at some other examples:
"She'll be walking her dog at around 10pm."
"I won't be working late this evening."
"I heard that it's goning to be snowing all night."
"This time next year I'm going to be living in London."