Sometimes it's useful to know what your finances will look like in the
future, such as determining when an account will reach zero.  Ledger
makes this easy to do, using the same period transactions as are used for
budgeting.  An example forecast report can be generated with:

@example
ledger --forecast "T>@{\$-500.00@}" register ^assets ^liabilities
@end example

This report continues outputting postings until the running total
is greater than $-500.00.  A final posting is always output, to
show you what the total afterwards would be.

Forecasting can also be used with the balance report, but by date
only, and not against the running total:

@example
ledger --forecast "d<[2010]" bal ^assets ^liabilities
@end example