diff --git a/CHANGELOG b/CHANGELOG
index fec85b480..44c548456 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,5 +1,9 @@
 # Nmap Changelog ($Id$); -*-text-*-
 
+o Removed some non-ANSI-C strftime format strings ("%F") and
+  locale-dependent formats ("%c") from NSE scripts and libraries.
+  C99-specified %F was noticed by Alex Weber. [Daniel Miller]
+
 o [Zenmap] Added Polish translation by Jacek Wielemborek.
 
 o [NSE] Added http-coldfusion-subzero. It detects Coldfusion 9 and 10
diff --git a/nselib/natpmp.lua b/nselib/natpmp.lua
index 4a8edfc3a..9eb69bcf3 100644
--- a/nselib/natpmp.lua
+++ b/nselib/natpmp.lua
@@ -9,7 +9,6 @@
 local bin = require "bin"
 local ipOps = require "ipOps"
 local nmap = require "nmap"
-local os = require "os"
 local stdnse = require "stdnse"
 _ENV = stdnse.module("natpmp", stdnse.seeall)
 
@@ -104,7 +103,7 @@ Response = {
 		
 			pos, self.time, self.ip = bin.unpack("<II", self.data, pos)
 			self.ip = ipOps.fromdword(self.ip)
-			self.time = os.date("%c", self.time)
+			self.time = stdnse.format_timestamp(self.time)
 			return true
 		end,
 		
diff --git a/nselib/rpc.lua b/nselib/rpc.lua
index 8d26f108e..4441a1b37 100644
--- a/nselib/rpc.lua
+++ b/nselib/rpc.lua
@@ -80,7 +80,6 @@ local bit = require "bit"
 local datafiles = require "datafiles"
 local math = require "math"
 local nmap = require "nmap"
-local os = require "os"
 local stdnse = require "stdnse"
 local string = require "string"
 local table = require "table"
@@ -3208,9 +3207,7 @@ Util =
         -- @param number of seconds since some given start time
         --        (the "epoch")
         -- @return string that represents time.
-        TimeToString = function(time) 
-            return os.date("!%F %H:%M", time)
-        end,
+        TimeToString = stdnse.format_timestamp,
 
         --- Converts the size in bytes to a human readable format
         --
diff --git a/scripts/bitcoin-info.nse b/scripts/bitcoin-info.nse
index 18e99f314..52c6d07ec 100644
--- a/scripts/bitcoin-info.nse
+++ b/scripts/bitcoin-info.nse
@@ -1,5 +1,4 @@
 local bitcoin = require "bitcoin"
-local os = require "os"
 local shortport = require "shortport"
 local stdnse = require "stdnse"
 local table = require "table"
@@ -57,7 +56,7 @@ action = function(host, port)
 	bcoin:close()
 
 	local result = {}
-	table.insert(result, ("Timestamp: %s"):format(os.date("%c", ver.timestamp)))
+	table.insert(result, ("Timestamp: %s"):format(stdnse.format_timestamp(ver.timestamp)))
 	table.insert(result, ("Network: %s"):format(NETWORK[ver.magic]))
 	table.insert(result, ("Version: %s"):format(ver.ver))
 	table.insert(result, ("Node Id: %s"):format(ver.nodeid))
diff --git a/scripts/gpsd-info.nse b/scripts/gpsd-info.nse
index 723267b58..bcfa086fa 100644
--- a/scripts/gpsd-info.nse
+++ b/scripts/gpsd-info.nse
@@ -95,7 +95,7 @@ action = function(host, port)
 	end
 
 	local output = {
-		("Time of fix: %s UTC"):format(os.date("%c", gps.Util.convertTime(gpsinfo.date, gpsinfo.time))),
+		("Time of fix: %s"):format(stdnse.format_timestamp(gps.Util.convertTime(gpsinfo.date, gpsinfo.time))),
 		("Coordinates: %.4f,%.4f"):format(tonumber(gpsinfo.latitude), tonumber(gpsinfo.longitude)),
 		("Speed: %s knots"):format(gpsinfo.speed)
 	}	
diff --git a/scripts/memcached-info.nse b/scripts/memcached-info.nse
index 7f79ebb3e..478dfb6a6 100644
--- a/scripts/memcached-info.nse
+++ b/scripts/memcached-info.nse
@@ -1,5 +1,4 @@
 local nmap = require "nmap"
-local os = require "os"
 local shortport = require "shortport"
 local stdnse = require "stdnse"
 local tab = require "tab"
@@ -42,7 +41,7 @@ local filter = {
 	
 	["pid"] = { name = "Process ID" },
 	["uptime"] = { name = "Uptime", func = function(v) return ("%d seconds"):format(v) end },
-	["time"] = { name = "Server time", func = function(v) return os.date("%c", v) end },
+	["time"] = { name = "Server time", func = stdnse.format_timestamp },
 	["pointer_size"] = { name = "Architecture", func = function(v) return v .. " bit" end },
 	["rusage_user"] = { name = "Used CPU (user)" },
 	["rusage_system"] = { name = "Used CPU (system)"},
diff --git a/scripts/ntp-info.nse b/scripts/ntp-info.nse
index 673c39d30..6ffbb1ad9 100644
--- a/scripts/ntp-info.nse
+++ b/scripts/ntp-info.nse
@@ -1,7 +1,6 @@
 local bin = require "bin"
 local comm = require "comm"
 local nmap = require "nmap"
-local os = require "os"
 local shortport = require "shortport"
 local stdnse = require "stdnse"
 local string = require "string"
@@ -90,7 +89,7 @@ action = function(host, port)
     -- the NTP4 reference above.
     tstamp = sec - 2208988800 + frac / 0x10000000
 
-    table.insert(output, string.format("receive time stamp: %s", os.date("%c", tstamp)))
+    table.insert(output, string.format("receive time stamp: %s", stdnse.format_timestamp(tstamp)))
   end
 
   status, bufrlres = comm.exchange(host, port, rlreq, {proto=port.protocol, timeout=TIMEOUT})
diff --git a/scripts/openlookup-info.nse b/scripts/openlookup-info.nse
index 86f7a78cc..6c259e5f3 100644
--- a/scripts/openlookup-info.nse
+++ b/scripts/openlookup-info.nse
@@ -1,6 +1,5 @@
 local comm = require "comm"
 local nmap = require "nmap"
-local os = require "os"
 local shortport = require "shortport"
 local stdnse = require "stdnse"
 local string = require "string"
@@ -163,12 +162,11 @@ local function formataddress(data)
 end
 
 local function formattime(data)
-	local FORMAT = "!%Y-%m-%d %H:%M:%S UTC"
 	local time = parsefloat(data)
 	if not time then
 		return
 	end
-	local human = os.date(FORMAT, time)
+	local human = stdnse.format_timestamp(time)
 	return time .. " (" .. human .. ")"
 end