Not necessarily - things change!
You tell you son - This weekend we are going fishing for the whole weekend.
But at 2 pm - the boss tells you must meet a client at the airport on Sat at 2 pm.
So you cannot take your son fishing - did you lie to him - of course not.
Things happen.
A lie is when you intentionally try to deceive someone.
You should follow what James in scripture says then, Lord willing we will go fishing all weekend. When you dont do it that way, your assuming control over future situations you don't and can't have. The future belongs to God, so scripturally you are boasting before God, all such boasting is evil.
James 4:13-17
New King James Version
Do Not Boast About Tomorrow
13 Come now, you who say, “Today or tomorrow we will go to such and such a city, spend a year there, buy and sell, and make a profit”; 14 whereas you do not know what
will happen tomorrow. For what
is your life? It is even a vapor that appears for a little time and then vanishes away. 15 Instead you
ought to say, “If the Lord wills, we shall live and do this or that.” 16 But now you boast in your arrogance. All such boasting is evil.
17 Therefore, to him who knows to do good and does not do
it, to him it is sin.
I also plan to do things every single day, I set goals. I have to consider God in the equation, and do not always consciously do so, I admit that is a failing of mine, but I also do often ask Him or tell Him I want to go do X thing, would like to do this or that, so I also acknowledge God in my choices.