Although short term horizons such as end of day, end of week, end of month matter in accounting, generally it is mere summing-up and the simplest mark to market processes that take place at these short term horizons.
No scenario analysis or mark to future activities are usually undertaken for such short periods, except for very large portfolios.
More far-sighted companies and government agencies may also use between ten and one hundred years.
The Forestry Commission in the UK plans over a century into the future.
Achieving simultaneous policy is quite difficult without an agreement, as those taking action early may be seriously disadvantaged in competition with those taking action late on a regulatory matter.