Hnck: fix epoch

2026-09-04T17:19:23Z

fix epoch

← Older revision		Revision as of 13:19, 4 September 2026
Line 5:		Line 5:
	local M = {}		local M = {}

	local EPOCH_UNIX = ~~1772229600~~ -- Unix timestamp of the epoch snapshot		local EPOCH_UNIX = 1786741200 -- Unix timestamp of the epoch snapshot
	local EPOCH_YEAR = 76 -- in-universe PC year at that snapshot		local EPOCH_YEAR = 84 -- in-universe PC year at that snapshot
	local YEAR_DAYS = 21 -- real days per in-universe year		local YEAR_DAYS = 14 -- real days per in-universe year



	-- Return the current in-universe year (PC, integer).		-- Return the current in-universe year (PC, integer).

DoomBot: load_modules: sync

2026-05-31T20:42:46Z

load_modules: sync

New page

-- Module:AttuCalendar
-- Haracalnde calendar arithmetic for the Attu Project wiki.
-- Epoch constants mirror scripts/misc/current_year.py; update both when /fix epoch runs.

local M = {}

local EPOCH_UNIX = 1772229600 -- Unix timestamp of the epoch snapshot
local EPOCH_YEAR = 76 -- in-universe PC year at that snapshot
local YEAR_DAYS = 21 -- real days per in-universe year

-- Return the current in-universe year (PC, integer).
function M.current_year()
local elapsed_days = math.floor((os.time() - EPOCH_UNIX) / 86400)
return EPOCH_YEAR + math.floor(elapsed_days / YEAR_DAYS)
end

-- Parse a Haracalnde date string and return a fractional year.
--
-- Accepts:
-- "d-m y PC" → positive fractional year (1 PC = 1.0, no year 0)
-- "d-m y TT" → negative fractional year (1 TT = -1.0)
-- "present" → current_year() as an integer (no fractional part)
--
-- The fractional part encodes month and day within the year so that dates
-- can be compared and used for pixel calculations.
function M.parse_date(s)
s = mw.text.trim(s)
if s:lower() == "present" then
return M.current_year()
end
local d, mo, y, era = s:match("^(%d+)-(%d+)%s+(%d+)%s+(%a+)$")
if not d then
error("AttuCalendar: cannot parse date: " .. tostring(s))
end
d = tonumber(d)
mo = tonumber(mo)
y = tonumber(y)
-- No year 0: 1 TT → -1, 1 PC → 1.
if era:upper() == "TT" then
y = -y
elseif era:upper() ~= "PC" then
error("AttuCalendar: unknown era: " .. era)
end
-- Fractional offset within year: months are 1-indexed, days are 1-indexed.
-- 12 months × 30 days = 360 days/year.
local frac = (mo - 1) / 12 + (d - 1) / 360
return y + frac
end

-- Wikitext-callable: years between two Haracalnde dates (absolute value).
-- {{#invoke:AttuCalendar|years_between|<date1>|<date2>[|<decimals>]}}
-- Either date may be "present". decimals defaults to 0.
function M.years_between(frame)
local args = frame.args
local d1_str = mw.text.trim(args[1] or "")
local d2_str = mw.text.trim(args[2] or "")
local decimals = math.max(0, math.floor(tonumber(mw.text.trim(args[3] or "")) or 0))

if d1_str == "" or d2_str == "" then
return 'AttuCalendar: years_between requires two date arguments'
end
local ok1, d1 = pcall(M.parse_date, d1_str)
local ok2, d2 = pcall(M.parse_date, d2_str)
if not ok1 then return 'AttuCalendar: ' .. tostring(d1) .. '' end
if not ok2 then return 'AttuCalendar: ' .. tostring(d2) .. '' end

return string.format("%." .. decimals .. "f", math.abs(d2 - d1))
end

-- Convert a date string to a fraction in [0, 1] relative to [period_start, period_end].
-- Returns nil if the date falls outside the period (clamped to 0 or 1 would hide bugs).
function M.to_frac(date_str, period_start_str, period_end_str)
local d = M.parse_date(date_str)
local ps = M.parse_date(period_start_str)
local pe = M.parse_date(period_end_str)
local span = pe - ps
if span == 0 then return 0 end
return (d - ps) / span
end

return M

Module:AttuCalendar - Revision history

Hnck: fix epoch

DoomBot: load_modules: sync