What is the ruling on meticulous future planning in the United States, where citizens calculate everything materially with pen and paper?

Planning for permissible worldly affairs is legitimate and does not contradict reliance on God, as long as the heart remains attached to Him. Saying "Insha'Allah" (God willing) does not negate planning; rather, it protects the servant from lying if what was promised does not materialize. The greater the importance of a matter, the more pressing the need to plan for it, and this includes recommended and obligatory religious duties. This is evidenced by Allah's saying: "And if they had intended to set out, they would surely have made some preparation for it," and His saying: "And prepare for them whatever you are able of power." Examples of this include the Prophet's (peace be upon him) arrangements for the Hijrah (migration), and Yusuf's (peace be upon him) plan for managing the drought crisis.