diff --git a/Aforc_ERA5/make_bry_wkb_ERA5.m b/Aforc_ERA5/make_bry_wkb_ERA5.m
index c29d3b309c84448b094388cd153b049074676c15..7d4097fee4c31ae251426c87ff448e2e7aa75f15 100644
--- a/Aforc_ERA5/make_bry_wkb_ERA5.m
+++ b/Aforc_ERA5/make_bry_wkb_ERA5.m
@@ -122,7 +122,7 @@ for Y=Ymin:Ymax
   close(nc)
 
   wkb_time=time;
-  wkb_cycle=wkb_time(end);
+  wkb_cycle=0;
 %
 % Create the boundary file
 %
diff --git a/Oforc_OGCM/make_OGCM_mercator.m b/Oforc_OGCM/make_OGCM_mercator.m
index 91cd92690c67ace64179848f639f8b02f1e23800..f72433683b0b37c6e66d7adf012ff27fe1f87267 100644
--- a/Oforc_OGCM/make_OGCM_mercator.m
+++ b/Oforc_OGCM/make_OGCM_mercator.m
@@ -228,7 +228,12 @@ if makeclim==1 | makebry==1
             OGCM_time=nc{'time'}(:);
             ntimes=length(OGCM_time);
             if ntimes==1
-                dt=30; % monthly files
+                dt = eomday(Y, M); % monthly files
+                %disp(['Number of days of the given month: ',num2str(dt)]);
+                if strcmp(OGCM, 'mercator')
+                    dt = eomday(Y, M) + 1 ;  % add +1 days to avoid problems 
+                                             % with mercator starting at first days month   
+                end
                 itolap_a=1; itolap_p=1;
                 itolap_tot=itolap_a + itolap_p;
                 disp(['Reduced overlap for monthly files'])
diff --git a/crocotools_param.m b/crocotools_param.m
index 8b310ce1396cce28d18bf8d520efe0a23096ba96..e1a593e83bfa8485a3895f55127288499411dccf 100644
--- a/crocotools_param.m
+++ b/crocotools_param.m
@@ -490,6 +490,9 @@ end
 rmdepth     = 2;
 %
 % Overlap parameters : nb of records around each sequence
+% => for SODA put itolap_a = itolap_p = 1
+% => for mercator daily put itolap_a = itolap_p = 2 
+%         (due to date of the month first day of month)
 %
 itolap_a    = 1;   % before
 itolap_p    = 1;   % after