diff --git a/lib/modules/Calendar_I.pmod/Austrian.pmod b/lib/modules/Calendar_I.pmod/Austrian.pmod
index 216139e91bcd13c9dab722b6ca239bc9e29f965c..5d5de09fe523375c0769ab3d468227185ab97111 100644
--- a/lib/modules/Calendar_I.pmod/Austrian.pmod
+++ b/lib/modules/Calendar_I.pmod/Austrian.pmod
@@ -1,6 +1,6 @@
 // by Martin Baehr <mbaehr@email.archlab.tuwien.ac.at>
 
-inherit Calendar.ISO:ISO;
+inherit Calendar_I.ISO:ISO;
 
 void create()
 {
diff --git a/lib/modules/Calendar_I.pmod/Gregorian.pmod b/lib/modules/Calendar_I.pmod/Gregorian.pmod
index c4d170c5d23fd7cd6dbb59dca476abaa2b68b502..60295814e7daa3ea0c1828ebf7f282016c426812 100644
--- a/lib/modules/Calendar_I.pmod/Gregorian.pmod
+++ b/lib/modules/Calendar_I.pmod/Gregorian.pmod
@@ -1,6 +1,6 @@
 // by Mirar 
 
-//! module Calendar
+//! module Calendar_I
 //! submodule Gregorian
 //!	time units:
 //!	<ref>Year</ref>, <ref>Month</ref>, <ref>Week</ref>, <ref>Day</ref>
@@ -20,7 +20,7 @@ mapping week_day_mapping,month_mapping;
 
 class _TimeUnit
 {
-   inherit Calendar._TimeUnit;
+   inherit Calendar_I._TimeUnit;
 
    program vYear=function_object(object_program(this_object()))->Year;
    program vDay=function_object(object_program(this_object()))->Day;
@@ -36,7 +36,7 @@ class _TimeUnit
 class Year
 {
 //! class Year
-//! 	A <ref>Calendar.time_unit</ref>. 
+//! 	A <ref>Calendar_I.time_unit</ref>.
 //!
 //!	Lesser units: <ref>Month</ref>, <ref>Week</ref>, <ref>Day</ref>
 //!	Greater units: none
diff --git a/lib/modules/Calendar_I.pmod/ISO.pmod b/lib/modules/Calendar_I.pmod/ISO.pmod
index 214f6a709b30af38922540416953b0a83cceab53..448c0090d557b06427aa231e8a5466b8e39c2096 100644
--- a/lib/modules/Calendar_I.pmod/ISO.pmod
+++ b/lib/modules/Calendar_I.pmod/ISO.pmod
@@ -1,6 +1,6 @@
 // IS-8601, international standard
 
-inherit Calendar.Gregorian:Gregorian;
+inherit Calendar_I.Gregorian:Gregorian;
 
 class Year
 {
diff --git a/lib/modules/Calendar_I.pmod/Julian.pmod b/lib/modules/Calendar_I.pmod/Julian.pmod
index 7c03a20b858cc0e31f5795e7de6f5f34fd9b1a64..bde39fa269ed5d9ca9758fc0e592143b0a053774 100644
--- a/lib/modules/Calendar_I.pmod/Julian.pmod
+++ b/lib/modules/Calendar_I.pmod/Julian.pmod
@@ -1,8 +1,8 @@
-inherit Calendar.Gregorian;
+inherit Calendar_I.Gregorian;
 
 class Year
 {
-  inherit Calendar.Gregorian.Year;
+  inherit Calendar_I.Gregorian.Year;
 
   int julian_day(int d) // jd%7 gives weekday, mon=0, sun=6
   {
@@ -18,13 +18,13 @@ class Year
 
 class Day
 {
-  inherit Calendar.Gregorian.Day;
+  inherit Calendar_I.Gregorian.Day;
 
   void create(int ... arg)
   {
     if (!sizeof(arg))
     {
-      int jd = Calendar.Gregorian.Day()->julian_day()-1721424;
+      int jd = Calendar_I.Gregorian.Day()->julian_day()-1721424;
       y = jd*100/36525+1;
       d = jd-(y-1)*36525/100;
     }
diff --git a/lib/modules/Calendar_I.pmod/Orthodox.pmod b/lib/modules/Calendar_I.pmod/Orthodox.pmod
index faa7de36e9f5f085cd08301914476fcda1d0969c..f71a9f1e2e72b8bba276fe1048f995094666d67c 100644
--- a/lib/modules/Calendar_I.pmod/Orthodox.pmod
+++ b/lib/modules/Calendar_I.pmod/Orthodox.pmod
@@ -1,10 +1,10 @@
 // by Mirar 
 
-inherit Calendar.Gregorian : christ;
+inherit Calendar_I.Gregorian : christ;
 
 class Year
 {
-   inherit Calendar.Gregorian.Year;
+   inherit Calendar_I.Gregorian.Year;
 
    int leap() // tack, hubbe... :-)
    {
diff --git a/lib/modules/Calendar_I.pmod/Stardate.pmod b/lib/modules/Calendar_I.pmod/Stardate.pmod
index a91e964fca62279d71949e5522cb65a7fa45aa73..2605dc19511ddfb1c44c119729110ea71d57415c 100644
--- a/lib/modules/Calendar_I.pmod/Stardate.pmod
+++ b/lib/modules/Calendar_I.pmod/Stardate.pmod
@@ -7,7 +7,7 @@
 
 class TNGDate
 {
-   inherit Calendar._TimeUnit;
+   inherit Calendar_I._TimeUnit;
 
    // 40759.5  2363-10-05  2584405
    // 47391.2  2370-05-23  2586827
@@ -31,7 +31,7 @@ class TNGDate
    {
       float jd;
       if (!sizeof(day))
-	 day=({Calendar.Gregorian.Second()});
+	 day=({Calendar_I.Gregorian.Second()});
       else if (floatp(day[0]))
       {
 	 from_stardate(day[0]);
diff --git a/lib/modules/Calendar_I.pmod/Swedish.pmod b/lib/modules/Calendar_I.pmod/Swedish.pmod
index 861bd0a7f8fb3c7690cf34fc7407f1c5452d66c2..a952e8ea134f0f827bda0bf195816f0defa67318 100644
--- a/lib/modules/Calendar_I.pmod/Swedish.pmod
+++ b/lib/modules/Calendar_I.pmod/Swedish.pmod
@@ -1,6 +1,6 @@
 // by Mirar 
 
-inherit Calendar.ISO:ISO;
+inherit Calendar_I.ISO:ISO;
 
 void create()
 {
diff --git a/lib/modules/Calendar_I.pmod/module.pmod b/lib/modules/Calendar_I.pmod/module.pmod
index 302ac793ecb0d90c75c69a52141294345dfc2cc0..cec29ccff139c58ecf007323e58e8367d01ac685 100644
--- a/lib/modules/Calendar_I.pmod/module.pmod
+++ b/lib/modules/Calendar_I.pmod/module.pmod
@@ -1,5 +1,5 @@
 
-//! module Calendar
+//! module Calendar_I
 //!    
 //!   This module implements calendar calculations, and base classes
 //!   for time units. 
@@ -82,7 +82,7 @@ string print_month(void|object month,void|mapping options)
    string res="";
 
    if (!month)  // resolv thing here is to avoid compile-time resolve
-      month=master()->resolv("Calendar")["Gregorian"]["Month"]();
+      month=master()->resolv("Calendar_I")["Gregorian"]["Month"]();
 
    options=(["mark_today":1,
 	     "week_space":3,