Help needed

I am creating a block which turns into different blocks according to whether it is daytime or nighttime. But my block always turns into the daytime form regardless of time of day. Sometimes, at nighttime, the block turns into the nighttime form of the block for a split second before turning into the daytime form. How do I fix this?

This is my procedure:

Event trigger - triggered by external call or when (global trigger): No additional trigger
If Is day in the provided world = true
  do  Replace block at x:x y:y z:z with [daytime form] keep state [false] keep NBT/inventory [false]
else if Is day in the provided world = false
  do Replace block at x:x y:y z:z with [nighttime form] keep state [false] keep NBT/inventory [false]

My procedure is placed under "Client display random tick"