diff --git a/config/action.d/sendmail-whois-lines.conf b/config/action.d/sendmail-whois-lines.conf
index a4b53b97..30cd84b8 100644
--- a/config/action.d/sendmail-whois-lines.conf
+++ b/config/action.d/sendmail-whois-lines.conf
@@ -12,7 +12,7 @@
 # Values:  CMD
 #
 actionstart = printf %%b "Subject: [Fail2Ban] <name>: started
-              Date: `date -u +"%%a, %%d %%h %%Y %%T +0000"`
+              Date: `LC_TIME=C date -u +"%%a, %%d %%h %%Y %%T +0000"`
               From: Fail2Ban <<sender>>
               To: <dest>\n
               Hi,\n
@@ -25,7 +25,7 @@ actionstart = printf %%b "Subject: [Fail2Ban] <name>: started
 # Values:  CMD
 #
 actionstop = printf %%b "Subject: [Fail2Ban] <name>: stopped
-             Date: `date -u +"%%a, %%d %%h %%Y %%T +0000"`
+             Date: `LC_TIME=C date -u +"%%a, %%d %%h %%Y %%T +0000"`
              From: Fail2Ban <<sender>>
              To: <dest>\n
              Hi,\n
@@ -46,7 +46,7 @@ actioncheck =
 # Values:  CMD
 #
 actionban = printf %%b "Subject: [Fail2Ban] <name>: banned <ip>
-            Date: `date -u +"%%a, %%d %%h %%Y %%T +0000"`
+            Date: `LC_TIME=C date -u +"%%a, %%d %%h %%Y %%T +0000"`
             From: Fail2Ban <<sender>>
             To: <dest>\n
             Hi,\n
diff --git a/config/action.d/sendmail-whois.conf b/config/action.d/sendmail-whois.conf
index f63fd36f..6b7b9383 100644
--- a/config/action.d/sendmail-whois.conf
+++ b/config/action.d/sendmail-whois.conf
@@ -12,7 +12,7 @@
 # Values:  CMD
 #
 actionstart = printf %%b "Subject: [Fail2Ban] <name>: started
-              Date: `date -u +"%%a, %%d %%h %%Y %%T +0000"`
+              Date: `LC_TIME=C date -u +"%%a, %%d %%h %%Y %%T +0000"`
               From: Fail2Ban <<sender>>
               To: <dest>\n
               Hi,\n
@@ -25,7 +25,7 @@ actionstart = printf %%b "Subject: [Fail2Ban] <name>: started
 # Values:  CMD
 #
 actionstop = printf %%b "Subject: [Fail2Ban] <name>: stopped
-             Date: `date -u +"%%a, %%d %%h %%Y %%T +0000"`
+             Date: `LC_TIME=C date -u +"%%a, %%d %%h %%Y %%T +0000"`
              From: Fail2Ban <<sender>>
              To: <dest>\n
              Hi,\n
@@ -46,7 +46,7 @@ actioncheck =
 # Values:  CMD
 #
 actionban = printf %%b "Subject: [Fail2Ban] <name>: banned <ip>
-            Date: `date -u +"%%a, %%d %%h %%Y %%T +0000"`
+            Date: `LC_TIME=C date -u +"%%a, %%d %%h %%Y %%T +0000"`
             From: Fail2Ban <<sender>>
             To: <dest>\n
             Hi,\n
diff --git a/config/action.d/sendmail.conf b/config/action.d/sendmail.conf
index 569b3bfa..db619a87 100644
--- a/config/action.d/sendmail.conf
+++ b/config/action.d/sendmail.conf
@@ -12,7 +12,7 @@
 # Values:  CMD
 #
 actionstart = printf %%b "Subject: [Fail2Ban] <name>: started
-              Date: `date -u +"%%a, %%d %%h %%Y %%T +0000"`
+              Date: `LC_TIME=C date -u +"%%a, %%d %%h %%Y %%T +0000"`
               From: Fail2Ban <<sender>>
               To: <dest>\n
               Hi,\n
@@ -25,7 +25,7 @@ actionstart = printf %%b "Subject: [Fail2Ban] <name>: started
 # Values:  CMD
 #
 actionstop = printf %%b "Subject: [Fail2Ban] <name>: stopped
-             Date: `date -u +"%%a, %%d %%h %%Y %%T +0000"`
+             Date: `LC_TIME=C date -u +"%%a, %%d %%h %%Y %%T +0000"`
              From: Fail2Ban <<sender>>
              To: <dest>\n
              Hi,\n
@@ -46,7 +46,7 @@ actioncheck =
 # Values:  CMD
 #
 actionban = printf %%b "Subject: [Fail2Ban] <name>: banned <ip>
-            Date: `date -u +"%%a, %%d %%h %%Y %%T +0000"`
+            Date: `LC_TIME=C date -u +"%%a, %%d %%h %%Y %%T +0000"`
             From: Fail2Ban <<sender>>
             To: <dest>\n
             Hi,\n