Timezone convertion started

test.lua

@@ -1,11 +1,77 @@
 dofile("wlancfg.lua")
 print("Initialize Wordclock")
 
+-- As we are located in central europe, we have GMT+1
+local TIMEZONE_OFFSET_WINTER = 1
+
+--Summer winter time convertion
+--See: https://arduinodiy.wordpress.com/2015/10/13/the-arduino-and-daylight-saving-time/
+--
+--As October has 31 days, we know that the last Sunday will always fall from the 25th to the 31st
+--So our check at the end of daylight saving will be as follows:
+--if (dow == 7 && mo == 10 && d >= 25 && d <=31 && h == 3 && DST==1)
+--{
+--setclockto 2 am;
+--DST=0;
+--}
+--
+--To start summertime/daylightsaving time on the last Sunday in March is mutatis mutandis the same:
+--if (dow == 7 && mo == 3 && d >= 25 && d <=31 && h ==2 && DST==0)
+--{
+--setclockto 3 am;
+--DST=1;
+--}
+function getLocalTime(year, month, day, hour, minutes, seconds,dow)
+  -- Always adapte the timezoneoffset:
+  hour = hour + (TIMEZONE_OFFSET_WINTER)
+
+  -- we are in 100% in the summer time
+  if (month > 3 and month < 10) then 
+    hour = hour + 1
+  -- October is not 100% Summer time
+  --FIXME elseif (month == 10 and 
+  end
+  
+  return year, month, day, hour, minutes, seconds
+end
+
+-- Convert a given month in english abr. to number from 1 to 12.
+-- On unknown arguments, zero is returned.
+function convertMonth(str)
+ if (str=="Jan") then
+  return 1
+ elseif (str == "Feb") then
+  return 2
+ elseif (str == "Mar") then
+  return 3
+ elseif (str == "Apr") then
+  return 4
+ elseif (str == "May") then
+  return 5
+ elseif (str == "Jun") then
+  return 6
+ elseif (str == "Jul") then
+  return 7
+ elseif (str == "Aug") then
+  return 8
+ elseif (str == "Sep") then
+  return 9
+ elseif (str == "Oct") then
+  return 10
+ elseif (str == "Nov") then
+  return 11
+ elseif (str == "Dec") then
+  return 12
+ else
+  return 0
+ end
+end
+
 function startTimeupdate()
   -- Found: http://thearduinoguy.org/using-an-esp8266-as-a-time-source-part-2/
   -- retrieve the current time from Google
   conn=net.createConnection(net.TCP, 0) 
- 
+  -- Send the HTTP request
   conn:on("connection",function(conn, payload)
     conn:send("HEAD / HTTP/1.1\r\n".. 
             "Host: google.com\r\n"..
@@ -13,13 +79,56 @@ function startTimeupdate()
             "User-Agent: Mozilla/4.0 (compatible; esp8266 Lua;)"..
             "\r\n\r\n") 
   end)
-            
+  -- Extract the time from the answer
   conn:on("receive", function(conn, payload)
-    print('Time: '..string.sub(payload,string.find(payload,"Date: ")
-           +6,string.find(payload,"Date: ")+35))
+    local timestr = string.sub(payload,string.find(payload,"Date: ")
+           +6,string.find(payload,"Date: ")+35)
+    -- time looks like: Tue, 12 Apr 2016 16:26:31 GMT
+    print('Time: '.. timestr)
+    local firstComma=string.find(timestr, ",")
+    dow=string.sub(timestr, 0, firstComma-1)
+    nextParts=string.sub(timestr, firstComma+1)
+    i=0
+    hourminsectxt=nil
+    -- Split the text at each space
+    for str in string.gmatch(nextParts, "([^ ]+)") do
+        if (i==0) then
+          day=str
+        elseif (i==1) then
+          month=convertMonth(str)
+        elseif (i==2) then
+          year=str
+        elseif (i==3) then
+         hourminsectxt=str
+        end
+        i=i+1
+    end
+    -- Extract the time
+    if (hourminsectxt ~= nil) then
+       i=0
+       -- split the text at each :
+       for str in string.gmatch(hourminsectxt, "([^:]+)") do
+        if (i==0) then
+          hour=str
+        elseif (i==1) then
+          minutes=str
+        elseif (i==2) then
+          seconds=str
+        end
+        i=i+1
+       end
+    end
+    print("---------------")
+    year, month, day, hour, minutes, seconds = getLocalTime(year, month, day, hour, minutes, seconds,dow)
+    print(year)
+    print(month)
+    print(day)
+    print(hour)
+    print(minutes)
+    print(seconds)
+    print("---------------")
     conn:close()
   end)
-  t = tmr.now()    
   conn:connect(80,'google.com')
 end