Module:DafYomi

local p = {}

function p.today (frame)
	return fromDate(os.date("!*t"), frame.args.format)
end

function p.date (frame)
	return fromDate(frame.args, frame.args.format)
end

function fromDate (dat, format)
	local res = mas_daf(dat)
	-- add 1 to daf (no daf aleph)
	if (format) then
		return (string.gsub((string.gsub(format, "%%m", res.mas)), "%%d", res.daf + 1))
	else
		return "''" .. res.mas .. "'' " .. (res.daf + 1)
	end
end

function mas_daf (dat)
	dat.hour = 0
	dat.min = 0
	dat.sec = 0
	
	dat = os.time(dat)
	local date0 = os.time({year=2005,month=2,day=28,hour=0,min=0,sec=0}) -- date before start of cycle
	
	local sinceS = dat - date0 + 200 -- for the unlikely event of anti-leap seconds
	local sinceD = math.floor(sinceS / 86400)
	local days = sinceD % 2711
	
	if (days == 0) then return {mas='Niddah', daf='72'} end
	
	-- each number is the number of dapim, which is 1 less than the last daf's number
	
	if (days <= 63) then return {mas='Berakhot',daf=days} end
	days = days - 63
	if (days <= 156) then return {mas='Shabbat',daf=days} end
	days = days - 156
	if (days <= 104) then return {mas='Eruvin',daf=days} end
	days = days - 104
	if (days <= 120) then return {mas='Pesachim',daf=days} end
	days = days - 120
	if (days <= 21) then return {mas='Shekalim',daf=days} end
	days = days - 21
	if (days <= 87) then return {mas='Yoma',daf=days} end
	days = days - 87
	if (days <= 55) then return {mas='Sukkah',daf=days} end
	days = days - 55
	if (days <= 39) then return {mas='Beitza',daf=days} end
	days = days - 39
	if (days <= 34) then return {mas='Rosh Hashanah',daf=days} end
	days = days - 34
	if (days <= 30) then return {mas="Ta'anit",daf=days} end
	days = days - 30
	if (days <= 31) then return {mas='Megillah',daf=days} end
	days = days - 31
	if (days <= 28) then return {mas="Mo'ed Katan",daf=days} end
	days = days - 28
	if (days <= 27) then return {mas='Chagigah',daf=days} end
	days = days - 27
	if (days <= 121) then return {mas='Yevamot',daf=days} end
	days = days - 121
	if (days <= 111) then return {mas='Ketubot',daf=days} end
	days = days - 111
	if (days <= 90) then return {mas='Nedarim',daf=days} end
	days = days - 90
	if (days <= 65) then return {mas='Nazir',daf=days} end
	days = days - 65
	if (days <= 48) then return {mas='Sotah',daf=days} end
	days = days - 48
	if (days <= 89) then return {mas='Gittin',daf=days} end
	days = days - 89
	if (days <= 81) then return {mas='Kiddushin',daf=days} end
	days = days - 81
	if (days <= 118) then return {mas='Bava Kamma',daf=days} end
	days = days - 118
	if (days <= 118) then return {mas='Bava Metzia',daf=days} end
	days = days - 118
	if (days <= 175) then return {mas='Bava Batra',daf=days} end
	days = days - 175
	if (days <= 112) then return {mas='Sanhedrin',daf=days} end
	days = days - 112
	if (days <= 23) then return {mas='Makkot',daf=days} end
	days = days - 23
	if (days <= 48) then return {mas='Shevuot',daf=days} end
	days = days - 48
	if (days <= 75) then return {mas='Avodah Zarah',daf=days} end
	days = days - 75
	if (days <= 13) then return {mas='Horayot',daf=days} end
	days = days - 13
	if (days <= 119) then return {mas='Zevachim',daf=days} end
	days = days - 119
	if (days <= 109) then return {mas='Menachot',daf=days} end
	days = days - 109
	if (days <= 141) then return {mas='Chullin',daf=days} end
	days = days - 141
	if (days <= 60) then return {mas='Bekhorot',daf=days} end
	days = days - 60
	if (days <= 33) then return {mas='Arakhin',daf=days} end
	days = days - 33
	if (days <= 33) then return {mas='Temurah',daf=days} end
	days = days - 33
	if (days <= 27) then return {mas='Keritot',daf=days} end
	days = days - 27
	if (days <= 21) then return {mas="Me'ilah",daf=days} end -- these 4 tractates are numbered consecutively
	if (days <= 24) then return {mas='Kinnim',daf=days} end
	if (days <= 32) then return {mas='Tamid',daf=days} end
	if (days <= 36) then return {mas='Middot',daf=days} end
	days = days - 36
	return {mas='Niddah',daf=days}
end

return p
Usage
