Different people and cultures believe different things for the answer to this question. The meaning of life as we perceive it is derived from philosophical and religious contemplation of, and scientific inquiries about existence, social ties, consciousness, and happiness.
A long-term financial plan should include these elements. Time Horizon. A plan should look at least  five to ten years into the future. Scope. A plan should consider all appropriated funds, but especially those funds that are used to account for the issues of top concern to elected officials and the community. Frequency.
How Long Should Your Business Plan Be? Depending on what you're using it for, a useful business plan can be any length, from a scrawl on the back of an envelope to, in the case of an especially detailed plan describing a complex enterprise, more than 100 pages. A typical business plan runs 15 to 20 pages, but there's room for wide variation from that norm.