diff --git a/README.md b/README.md
index 3c46605..7ea2387 100644
--- a/README.md
+++ b/README.md
@@ -10,6 +10,7 @@ check_expire follows the usual Nagios rules. The options are:
 * -c: critical threshold in days
 * -w: warning threshold in days
 * -v: verbose details in output
+* -u: unixtime output
 
 ## Installation
 
@@ -37,8 +38,8 @@ object CheckCommand "expiration" {
 apply Service "expiration" {
   import "generic-service"
 
-  check_command = "expiration" 
-  
+  check_command = "expiration"
+
   assign where host.address && host.vars.monitor_expiration
 }
 ```
@@ -48,15 +49,26 @@ And a possible use:
 ```
 object Host "bortzmeyer-org" {
   ...
-  
+
   address = "bortzmeyer.org"
 
   vars.monitor_expiration = true
   vars.expiration_verbose = true
-  
+
 }
 ```
 
+## Zabbix configuration
+
+For monitoring systems that do not rely on exit codes but on calculation mechanism based on the metric they receive you can use the `-u` option that will only return the expiration date in unixtime format.
+
+For instance, you can use the following in zabbix 5.4:
+
+* item: `check_expire["-H","{HOST.CONN}","-u"]`
+* trigger (30 days before expiration): `last(/check_expire["-H","{HOST.CONN}","-u"])-now()<2592000`
+
+Where `2592000` is the number of seconds in 30 days.
+
 ## License
 
 GPL. See LICENSE.
@@ -67,6 +79,4 @@ Stéphane Bortzmeyer <stephane+chapril@bortzmeyer.org>.
 
 ## Reference site
 
-https://forge.chapril.org/bortzmeyer/check_expire Use the Gitea issue tracker to report bugs or wishes. 
-
-
+https://forge.chapril.org/bortzmeyer/check_expire Use the Gitea issue tracker to report bugs or wishes.
diff --git a/check_expire b/check_expire
index a60fba0..63797df 100755
--- a/check_expire
+++ b/check_expire
@@ -42,10 +42,11 @@ verbose = False
 domain = None
 critical_t = datetime.timedelta(days=2)
 warning_t = datetime.timedelta(days=7)
+unixtime = False
 # TODO implement timeout for HTTPS requests. -t option. Does Requests allow it?
 
 def usage(msg=None):
-    print("Usage: %s -H domain-name [-c critical -w warning]" % sys.argv[0], end="")
+    print("Usage: %s -H domain-name [-c critical -w warning -u unixtime]" % sys.argv[0], end="")
     if msg is not None and msg != "":
         print(" (%s)" % msg)
     else:
@@ -80,8 +81,8 @@ def ok(msg=None):
     sys.exit(STATE_OK)
 
 try:
-    optlist, args = getopt.getopt (sys.argv[1:], "c:hH:vVw:",
-                                   ["critical=", "expiration", "help", "verbose", "version", "warning="])
+    optlist, args = getopt.getopt (sys.argv[1:], "c:hH:vVw:u",
+                                   ["critical=", "expiration", "help", "verbose", "version", "warning=", "unixtime"])
     for option, value in optlist:
         if option == "--critical" or option == "-c":
             critical_t = datetime.timedelta(days=int(value))
@@ -97,6 +98,8 @@ try:
             sys.exit(STATE_OK)
         elif option == "--warning" or option == "-w":
             warning_t = datetime.timedelta(days=int(value))
+        elif option == "--unixtime" or option == "-u":
+            unixtime = True
         else:
             # Should never occur, it is trapped by getopt
             print("Unknown option %s" % option)
@@ -136,6 +139,9 @@ for event in rdap["events"]:
                     print("No recognized format for datetime \"%s\"" % event["eventDate"])
                     sys.exit(STATE_UNKNOWN)
         now = datetime.datetime.now(tz=UTCINFO)
+        if unixtime == True:
+            print(int(expiration.strftime("%s")))
+            sys.exit(STATE_OK)
         if expiration < now:
             error("domain %s is already expired (%s ago)" % (domain, (now-expiration)))
         rest = expiration-now
@@ -146,5 +152,3 @@ for event in rdap["events"]:
         else:
             ok("expires in %s." % (rest))
 error("No expiration found")
-
-