Simple pilot age calculator for Endless Sky

pilot_age.lua

local start = {year = 3013, month = 11, day = 16}

local pilots = {
	{year= 3045, month= 9, day= 10},
	{year= 3020, month= 4, day= 18},
	{year= 3043, month= 5, day= 21},
	{year= 3027, month= 12, day= 30},
	{year= 3023, month= 11, day= 24},
	{year= 3027, month= 2, day= 8},
	{year= 3030, month= 6, day= 26},
	{year= 3023, month= 9, day= 4},
}

local mdays = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}

local dm_to_dy = {}
do
	local curr_day = 1
	for month= 1, 12 do
		local dme = {}
		for day = 1, mdays[month] do
			dme[day] = curr_day
			curr_day = curr_day + 1
		end
		dm_to_dy[month] = dme
	end
end

local leaps = {}
do
	local curls = 0
	for year = 3014, 4000 do
		if year % 4 == 0 and (year % 100 ~= 0 or year % 400 == 0) then
			curls = curls + 1
		end
		leaps[year] = curls
	end
end

local function days_since_start(date)
	local yeet = date.year - 3014
	local deet = dm_to_dy[date.month][date.day]
	return yeet * 365 + deet + leaps[date.year] - 46
end

local total_age = 0
for pid, pill in ipairs(pilots) do
	local age = days_since_start(pill)
	print(('%d. %d/%d/%d (%d days)'):format(pid, pill.year, pill.month, pill.day, age))
	total_age = total_age + age
end

local age_years = math.floor(total_age / 365.25)
print(('%d total years (%d total days)'):format(age_years, total_age))