Calculate weekday

gui.lua

@@ -31,8 +31,7 @@ local function show_calendar(player_name, ordinal, wanted_months, wanted_years)
 		wanted_dmonths = wanted_dmonths + 1
 		wanted_dyears = wanted_dyears + 1
 	end
-	local weekday = 0
-	local formspec = "formspec_version[3]size["..(calendar.WEEK_DAYS+2)..",9]"
+	local formspec = "formspec_version[3]size["..(calendar.WEEK_DAYS+2)..",10]"
 	if ordinal then
 		formspec = formspec .. "label[0.5,0.5;"..F(S("@1, year @2", calendar.month_names[wanted_months+1], wanted_dyears)).."]"
 	else
@@ -42,6 +41,7 @@ local function show_calendar(player_name, ordinal, wanted_months, wanted_years)
 	local tdays = 0
 	tdays = tdays + wanted_years * (calendar.MONTHS * calendar.MONTH_DAYS)
 	tdays = tdays + wanted_months * calendar.MONTH_DAYS
+	local weekday = calendar.get_weekday(tdays)
 
 	local x, y = 0.75, 1.2
 	for w=1, #calendar.weekday_names_short do

init.lua

@@ -23,6 +23,7 @@ calendar.YEAR_DAYS = calendar.MONTHS * calendar.MONTH_DAYS
 calendar.weekday_names = { S("Monday"), S("Tuesday"), S("Wednesday"), S("Thursday"), S("Friday"), S("Saturday"), S("Sunday") }
 calendar.weekday_names_short = { S("Mo"), S("Tu"), S("We"), S("Th"), S("Fr"), S("Sa"), S("Su") }
 calendar.WEEK_DAYS = #calendar.weekday_names
+calendar.FIRST_WEEK_DAY = 0
 
 local holidays = {
 	{ name = S("New Year's Eve"),
@@ -67,6 +68,12 @@ calendar.get_holidays = function(total_days)
 	return found_holidays
 end
 
+-- Returny weekday number
+-- * total_days: elapsed days since start of world
+calendar.get_weekday = function(total_days)
+	return (total_days + calendar.FIRST_WEEK_DAY) % calendar.WEEK_DAYS
+end
+
 -- Returns day, month, year, days in year
 -- * days: elapsed days since start of world
 -- * ordinal: if true, use ordinal numbers (day, month, year start counting at 1).