diff --git a/dfhack/include/modules/Materials.h b/dfhack/include/modules/Materials.h
index 803443313..73641e10c 100644
--- a/dfhack/include/modules/Materials.h
+++ b/dfhack/include/modules/Materials.h
@@ -50,6 +50,8 @@ namespace DFHack
     {
         char part[128];
         std::vector<uint32_t> colorlist;
+        uint32_t startdate; /* in days */
+        uint32_t enddate; /* in days */
     };
     
     struct t_creaturecaste
diff --git a/dfhack/modules/Materials.cpp b/dfhack/modules/Materials.cpp
index 9cdab2ffc..417b5a53c 100644
--- a/dfhack/modules/Materials.cpp
+++ b/dfhack/modules/Materials.cpp
@@ -304,6 +304,8 @@ bool Materials::ReadCreatureTypesEx (void)
     uint32_t bodypart_singular_offset = mem->getOffset ("bodypart_singular_vector");
     uint32_t bodypart_plural_offset = mem->getOffset ("bodypart_plural_vector");
     uint32_t color_modifier_part_offset = mem->getOffset ("color_modifier_part");
+    uint32_t color_modifier_startdate_offset = mem->getOffset ("color_modifier_startdate");
+    uint32_t color_modifier_enddate_offset = mem->getOffset ("color_modifier_enddate");
     uint32_t size = p_races.size();
     uint32_t sizecas = 0;
     uint32_t sizecolormod;
@@ -341,6 +343,8 @@ bool Materials::ReadCreatureTypesEx (void)
                 for(uint32_t l = 0; l < sizecolorlist; l++)
                     caste.ColorModifier[k].colorlist[l] = p_colorlist[l];
                 p->readSTLString( p_colormod[k] + color_modifier_part_offset, caste.ColorModifier[k].part, sizeof(caste.ColorModifier[k].part));
+                caste.ColorModifier[k].startdate = p->readDWord( p_colormod[k] + color_modifier_startdate_offset );
+                caste.ColorModifier[k].enddate = p->readDWord( p_colormod[k] + color_modifier_enddate_offset );
             }
 
             /* body parts */
diff --git a/examples/materialtest.cpp b/examples/materialtest.cpp
index ccd62c0ec..16fdeaf01 100644
--- a/examples/materialtest.cpp
+++ b/examples/materialtest.cpp
@@ -117,7 +117,10 @@ int main (int numargs, const char ** args)
             cout << endl;
             for(uint32_t k = 0; k < castes[j].ColorModifier.size(); k++)
             {
-                cout << "    colormod[" << castes[j].ColorModifier[k].part << "] ";
+                cout << "    colormod[" << castes[j].ColorModifier[k].part;
+                if(castes[j].ColorModifier[k].startdate>0)
+                    cout << " start:" << castes[j].ColorModifier[k].startdate << " days, end:" << castes[j].ColorModifier[k].enddate << " days";
+                cout << "] ";
                 for(uint32_t l = 0; l < castes[j].ColorModifier[k].colorlist.size(); l++)
                 {
                     if( castes[j].ColorModifier[k].colorlist[l] < Materials->color.size() )
diff --git a/output/Memory.xml b/output/Memory.xml
index fb9b9e63d..a4bc527b6 100755
--- a/output/Memory.xml
+++ b/output/Memory.xml
@@ -1445,6 +1445,8 @@ map_data_1b60_offset          0x1B9c
         Castes
         ======
         <Offset name="color_modifier_part">0x70</Offset>
+        <Offset name="color_modifier_startdate">0x64</Offset>
+        <Offset name="color_modifier_enddate">0x68</Offset>
         <Offset name="caste_bodypart_vector">0x51C</Offset>
         <Offset name="caste_color_modifiers">0xACC</Offset>
         <Offset name="caste_attributes">0x654</Offset>