close, equity
Prints a sample "closing" transaction bringing specified account
balances to zero, and an inverse "opening" transaction restoring the
same account balances.

If like most people you split your journal files by time, eg by year: at
the end of the year you can use this command to "close out" your asset
and liability (and perhaps equity) balances in the old file, and
reinitialise them in the new file. This helps ensure that report
balances remain correct whether you are including old files or not.
(Because all closing/opening transactions except the very first will
cancel out - see example below.)

Some people also use this command to close out revenue and expense
balances at the end of an accounting period. This properly records the
period's profit/loss as "retained earnings" (part of equity), and allows
the accounting equation (A-L=E) to balance, which you could then check
by the bse report's zero total.

_FLAGS

You can print just the closing transaction by using the --close flag, or
just the opening transaction with the --open flag.

Their descriptions are closing balances and opening balances by default;
you can customise these with the --close-desc and --open-desc options.

Just one balancing equity posting is used by default, with the amount
left implicit. The default account name is
equity:opening/closing balances. You can customise the account name(s)
with --close-acct and --open-acct. (If you specify only one of these, it
will be used for both.)

With --x/--explicit, the equity posting's amount will be shown
explicitly, and if it involves multiple commodities, there will be a
separate equity posting for each commodity (as in the print command).

With --interleaved, each equity posting is shown next to the posting it
balances (good for troubleshooting).

close and prices

Transaction prices are ignored (and discarded) by closing/opening
transactions, by default. With --show-costs, they are preserved; there
will be a separate equity posting for each cost in each commodity. This
means balance -B reports will look the same after the transition. Note
if you have many foreign currency or investment transactions, this will
generate very large journal entries.

close date

The default closing date is yesterday, or the journal's end date,
whichever is later.

Unless you are running close on exactly the first day of the new period,
you'll want to override the closing date. This is done by specifying a
report end date, where "last day of the report period" will be the
closing date. The opening date is always the following day. So to close
on (end of) 2020-12-31 and open on (start of) 2021-01-01, any of these
will work:

  end date argument   explanation
  ------------------- ------------------------------------------------
  -e 2021-01-01       end dates are exclusive
  -e 2021             equivalent, per smart dates
  -p 2020             equivalent, the period's begin date is ignored
  date:2020           equivalent query

Example: close asset/liability accounts for file transition

Carrying asset/liability balances from 2020.journal into a new file for
2021:

$ hledger close -f 2020.journal -p 2020 assets liabilities
# copy/paste the closing transaction to the end of 2020.journal
# copy/paste the opening transaction to the start of 2021.journal

Or:

$ hledger close -f 2020.journal -p 2020 assets liabilities --open  >> 2021.journal  # add 2021's first transaction
$ hledger close -f 2020.journal -p 2020 assets liabilities --close >> 2020.journal  # add 2020's last transaction

Now,

$ hledger bs -f 2021.journal                   # just new file - balances correct
$ hledger bs -f 2020.journal -f 2021.journal   # old and new files - balances correct
$ hledger bs -f 2020.journal                   # just old files - balances are zero ?
                                               # (exclude final closing txn, see below)

Hiding opening/closing transactions

Although the closing/opening transactions cancel out, they will be
visible in reports like print and register, creating some visual
clutter. You can exclude them all with a query, like:

$ hledger print not:desc:'opening|closing'             # less typing
$ hledger print not:'equity:opening/closing balances'  # more precise

But when reporting on multiple files, this can get a bit tricky; you may
need to keep the earliest opening balances, for a historical register
report; or you may need to suppress a closing transaction, to see
year-end balances. If you find yourself needing more precise queries,
here's one solution: add more easily-matched tags to opening/closing
transactions, like this:

; 2019.journal
2019-01-01 opening balances  ; earliest opening txn, no tag here
...
2019-12-31 closing balances  ; clopen:2020
...

; 2020.journal
2020-01-01 opening balances  ; clopen:2020
...
2020-12-31 closing balances  ; clopen:2021
...

; 2021.journal
2021-01-01 opening balances  ; clopen:2021
...

Now with

; all.journal
include 2019.journal
include 2020.journal
include 2021.journal

you could do eg:

$ hledger -f all.journal reg -H checking not:tag:clopen
    # all years checking register, hiding non-essential opening/closing txns

$ hledger -f all.journal bs -p 2020 not:tag:clopen=2020
    # 2020 year end balances, suppressing 2020 closing txn

close and balance assertions

The closing and opening transactions will include balance assertions,
verifying that the accounts have first been reset to zero and then
restored to their previous balance. These provide valuable error
checking, alerting you when things get out of line, but you can ignore
them temporarily with -I or just remove them if you prefer.

You probably shouldn't use status or realness filters (like -C or -R or
status:) with close, or the generated balance assertions will depend on
these flags. Likewise, if you run this command with --auto, the balance
assertions would probably always require --auto.

Multi-day transactions (where some postings have a different date) break
the balance assertions, because the money is temporarily "invisible"
while in transit:

2020/12/30 a purchase made in december, cleared in the next year
    expenses:food          5
    assets:bank:checking  -5  ; date: 2021/1/2

To fix the assertions, you can add a temporary account to track such
in-transit money (splitting the multi-day transaction into two
single-day transactions):

; in 2020.journal:
2020/12/30 a purchase made in december, cleared in the next year
    expenses:food          5
    liabilities:pending

; in 2021.journal:
2021/1/2 clearance of last year's pending transactions
    liabilities:pending    5 = 0
    assets:bank:checking

Example: close revenue/expense accounts to retained earnings

For this, use --close to suppress the opening transaction, as it's not
needed. Also you'll want to change the equity account name to your
equivalent of "equity:retained earnings".

Closing 2021's first quarter revenues/expenses:

$ hledger close -f 2021.journal --close revenues expenses -p 2021Q1 \
    --close-acct='equity:retained earnings' >> 2021.journal

The same, using the default journal and current year:

$ hledger close --close revenues expenses -p Q1 \
    --close-acct='equity:retained earnings' >> $LEDGER_FILE

Now, the first quarter's balance sheet should show a zero (unless you
are using @/@@ notation without equity postings):

$ hledger bse -p Q1

And we must suppress the closing transaction to see the first quarter's
income statement (using the description; not:'retained earnings' won't
work here):

$ hledger is -p Q1 not:desc:'closing balances'
