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wanderbooks/bookspec/examples/depreciation-final-month-by-days.toml
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swaitsandClaude Opus 5.5 b0a9fd8ad4 P3: depreciation straight-line by days through the final month, schedules by day (defects 22, 9, D-37)
The final month takes what the months before leave, spread over its days;
a disposed asset stops on its disposal day. A skipped month is caught up
in the month the run is made; a reversed run un-posts its month. New
schedules spread by day; equal-months schedules must start on the 1st.
Amounts round to the currency's own minor unit. Kani and Lean proofs; an
exhaustive search over runs, reversals and disposals.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01T3gXMVt7XJPi6ens1or9Dj
2026-10-21 14:04:11 -06:00

94 lines
2.3 KiB
TOML

id = "depreciation-final-month-by-days"
title = "Straight-line depreciation by the day through the life's final month"
rule = "Depreciation through a day of an asset's final month is the depreciation before that month plus the final month's share for the days held, never the whole remaining cost."
status = "CONVENTION"
sources = ["ASC 360-10-35-4"]
tags = ["depreciation", "straight-line", "final-month", "p3-defect-22"]
[setup]
currency = "USD"
fiscal_year_start = "01-01"
basis = "accrual"
rounding = "half-away-from-zero"
[[setup.accounts]]
code = "1000"
name = "Bank"
type = "asset"
[[setup.accounts]]
code = "1500"
name = "Equipment"
type = "asset"
[[setup.accounts]]
code = "1510"
name = "Accumulated Depreciation"
type = "asset"
[[setup.accounts]]
code = "3000"
name = "Capital"
type = "equity"
[[setup.accounts]]
code = "6200"
name = "Depreciation Expense"
type = "expense"
# Asset X: 12,000.00, no salvage, 12 months from 2026-01-01. Its life is
# 2026-01-01 through 2026-12-31; December is its final month.
[[setup.assets]]
id = "X"
description = "Asset X"
cost = "12000.00"
salvage = "0.00"
life_months = 12
in_service = "2026-01-01"
method = "straight_line"
cost_account = "1500"
accumulated_account = "1510"
expense_account = "6200"
[[events]]
date = "2026-01-01"
description = "Capital"
lines = [
{ account = "1000", side = "debit", amount = "12000.00" },
{ account = "3000", side = "credit", amount = "12000.00" },
]
[[events]]
date = "2026-01-01"
description = "Bought asset X"
lines = [
{ account = "1500", side = "debit", amount = "12000.00" },
{ account = "1000", side = "credit", amount = "12000.00" },
]
# Hand check (worked without the code): 12,000.00 / 12 = 1,000.00 a month.
# Through Dec 15: January..November, 11 x 1,000.00 = 11,000.00, plus
# December's 1,000.00 x 15/31 = 483.870... -> 483.87 (half away from zero).
# Accumulated 11,483.87; book value 12,000.00 - 11,483.87 = 516.13.
[[expect]]
query = "depreciation_schedule"
asset = "X"
as_of = "2026-12-15"
[expect.values]
"2026-11" = "1000.00"
"2026-12" = "483.87"
accumulated = "11483.87"
book_value = "516.13"
# Hand check: through the life's last day, the whole of it.
[[expect]]
query = "depreciation_schedule"
asset = "X"
as_of = "2026-12-31"
[expect.values]
"2026-12" = "1000.00"
accumulated = "12000.00"
book_value = "0.00"