diff --git a/scripts/http-date.nse b/scripts/http-date.nse
index e16094af5..ab7320cf4 100644
--- a/scripts/http-date.nse
+++ b/scripts/http-date.nse
@@ -18,7 +18,7 @@ sent, so the difference includes at least the duration of one RTT.
 -- |_http-date: Thu, 02 Aug 2012 22:07:12 GMT; -3m51s from local time.
 --
 -- @xmloutput
--- <elem key="date">2012-08-02T23:07:12Z</elem>
+-- <elem key="date">2012-08-02T23:07:12+00:00</elem>
 -- <elem key="delta">-231</elem>
 
 author = "David Fifield"
@@ -31,8 +31,7 @@ categories = {"discovery", "safe"}
 portrule = shortport.http
 
 action = function(host, port)
-	-- Get the local date in UTC.
-	local request_date = os.date("!*t")
+	local request_time = os.time()
 	local response = http.get(host, port, "/")
 	if not response.status or not response.header["date"] then
 		return
@@ -42,14 +41,14 @@ action = function(host, port)
 	if not response_date then
 		return
 	end
+	local response_time = stdnse.date_to_timestamp(response_date)
 
 	local output_tab = stdnse.output_table()
-	-- ISO 8601 date and time.
-	output_tab.date = os.date("%Y-%m-%dT%H:%M:%SZ", os.time(response_date))
-	output_tab.delta = os.difftime(os.time(response_date), os.time(request_date))
+	output_tab.date = stdnse.format_timestamp(response_time, 0)
+	output_tab.delta = os.difftime(response_time, request_time)
 
 	local output_str = string.format("%s; %s from local time.",
-		response.header["date"], stdnse.format_difftime(response_date, request_date))
+		response.header["date"], stdnse.format_difftime(os.date("!*t", response_time), os.date("!*t", request_time)))
 
 	return output_tab, output_str
 end
diff --git a/scripts/smb-os-discovery.nse b/scripts/smb-os-discovery.nse
index 96629cd76..11be42802 100644
--- a/scripts/smb-os-discovery.nse
+++ b/scripts/smb-os-discovery.nse
@@ -57,7 +57,7 @@ will speed up the script on targets that do not allow guest access.
 -- |   FQDN: Sql2008.lab.test.local
 -- |   NetBIOS computer name: SQL2008
 -- |   NetBIOS domain name: LAB
--- |_  System time: 2011-04-20 13:34:06 UTC-5
+-- |_  System time: 2011-04-20T13:34:06-05:00
 --
 --@xmloutput
 -- <elem key="OS">Windows Server (R) 2008 Standard 6001 Service Pack 1 (Windows Server (R) 2008 Standard 6.0)</elem>
@@ -67,7 +67,7 @@ will speed up the script on targets that do not allow guest access.
 -- <elem key="FQDN">Sql2008.lab.test.local</elem>
 -- <elem key="NetBIOS computer name">SQL2008</elem>
 -- <elem key="NetBIOS domain name">LAB</elem>
--- <elem key="System time">2011-04-20 13:34:06 UTC-5</elem>
+-- <elem key="System time">2011-04-20T13:34:06-05:00</elem>
 
 author = "Ron Bowes"
 license = "Same as Nmap--See http://nmap.org/book/man-legal.html"
@@ -125,8 +125,8 @@ action = function(host)
 	if (result['os'] and result['lanmanager']) then
 		os_string = string.format( "%s (%s)", get_windows_version( result['os'] ), result['lanmanager'] )
 	end
-	if (result['date'] and result['timezone_str']) then
-		time_string = string.format("%s%+03d%02d", os.date("%Y-%m-%dT%H:%M:%S", result.time), result.timezone, math.abs(math.fmod(result.timezone, 1)) * 60)
+	if (result['time'] and result['timezone']) then
+		time_string = stdnse.format_timestamp(result.time, result.timezone * 60 * 60)
 	end
 	
 	
diff --git a/scripts/ssl-cert.nse b/scripts/ssl-cert.nse
index b3c6ba51d..eb23cd3dd 100644
--- a/scripts/ssl-cert.nse
+++ b/scripts/ssl-cert.nse
@@ -96,8 +96,8 @@ certificate.
 --   <elem key="bits">2048</elem>
 -- </table>
 -- <table key="validity">
---   <elem key="notBefore">2011-03-23T00:00:00Z</elem>
---   <elem key="notAfter">2013-04-01T23:59:59Z</elem>
+--   <elem key="notBefore">2011-03-23T00:00:00+00:00</elem>
+--   <elem key="notAfter">2013-04-01T23:59:59+00:00</elem>
 -- </table>
 -- <elem key="md5">bf47cecad861efa77d1488ad4a73cb5b</elem>
 -- <elem key="sha1">d8465221467a0d153df09f2eaf6d439002139a68</elem>
@@ -183,10 +183,6 @@ local function name_to_table(name)
   return output
 end
 
-local function format_time(t)
-    return os.date("%Y-%m-%dT%H:%M:%SZ", os.time(t))
-end
-
 local function output_tab(cert)
     local o = stdnse.output_table()
     o.subject = name_to_table(cert.subject)
@@ -194,7 +190,7 @@ local function output_tab(cert)
     o.pubkey = cert.pubkey
     o.validity = {}
     for k, v in pairs(cert.validity) do
-      o.validity[k] = format_time(v)
+      o.validity[k] = stdnse.format_timestamp(stdnse.date_to_timestamp(v, 0), 0)
     end
     o.md5 = stdnse.tohex(cert:digest("md5"))
     o.sha1 = stdnse.tohex(cert:digest("sha1"))
diff --git a/scripts/ssl-date.nse b/scripts/ssl-date.nse
index 99dbac4d1..58d87a989 100644
--- a/scripts/ssl-date.nse
+++ b/scripts/ssl-date.nse
@@ -38,7 +38,7 @@ end
 -- |_ssl-date: 2012-08-02T18:29:31Z; +4s from local time.
 --
 -- @xmloutput
--- <elem key="date">2012-08-02T18:29:31Z</elem>
+-- <elem key="date">2012-08-02T18:29:31+00:00</elem>
 -- <elem key="delta">4</elem>
 
 --
@@ -164,7 +164,7 @@ action = function(host, port)
 		status, result = extract_time(response)
 		if status then
 			local output = {
-				date = os.date("!%Y-%m-%dT%H:%M:%SZ",result),
+				date = stdnse.format_timestamp(result, 0),
 				delta = os.difftime(result, now),
 			}
 			return output, string.format("%s; %s from local time.", output.date,