diff --git a/init.lua b/init.lua
index 278f3bf..d9cd1bd 100644
--- a/init.lua
+++ b/init.lua
@@ -11,11 +11,14 @@ local meseclock_toggle_timer = function (pos)
    else
       local node = minetest.get_node(pos)
       local nodedef = minetest.registered_nodes[node.name]
+      local meta = minetest.get_meta(pos)
+      local meta_on_interval = meta:get_int("on_time") or default_on_interval
+      local meta_off_interval = meta:get_int("off_time") or default_off_interval
 
       if (nodedef.__mesecon_state == "on") then
-         timer:start(default_on_interval)
+         timer:start(meta_on_interval)
       else
-         timer:start(default_off_interval)
+         timer:start(meta_off_interval)
       end
    end
 end
@@ -32,10 +35,35 @@ local meseclock_on_timer = function (pos)
    meseclock_toggle_timer(pos)
 end
 
+local meseclock_make_formspec = function (pos)
+   local meta = minetest.get_meta(pos)
+   if meta:get_string("on_time") == "" then meta:set_string("on_time", "1") end
+   if meta:get_string("off_time") == "" then meta:set_string("off_time", "1") end
+
+   meta:set_string(
+      "formspec", "size[6,2.5]" ..
+      "field[0.3, 0;3,2;on_time;" .. S("On time (seconds)") .. ":;${on_time}]" ..
+      "field[3.3, 0;3,2;off_time;" .. S("Off time (seconds)") .. ":;${off_time}]" ..
+      "button_exit[0.3,0.5;2,3;;" .. S("Save") .. "]"
+   )
+end
+
 local meseclock_on_construct = function (pos)
+   meseclock_make_formspec(pos)
    meseclock_toggle_timer(pos)
 end
 
+local meseclock_on_receive_fields = function (pos, _, fields, sender)
+   if not fields.on_time then return end
+   if minetest.is_protected(pos, sender:get_player_name()) then return end
+
+   local meta = minetest.get_meta(pos)
+   meta:set_string("on_time", fields.on_time or to_string(default_on_time))
+   meta:set_string("off_time", fields.off_time or to_string(default_off_time))
+
+   meseclock_make_formspec(pos)
+end
+
 local node_defaults = {
    description = S("Mesecons Clock"),
    drawtype = "nodebox",
@@ -60,6 +88,7 @@ local node_defaults = {
    on_blast = mesecon.on_blastnode,
    drop = "mesecons_clock:clock_off",
    on_construct = meseclock_on_construct,
+   on_receive_fields = meseclock_on_receive_fields,
    on_punch = function (pos, _, clicker)
       if minetest.is_protected(pos, clicker and clicker:get_player_name() or "") then
          return
diff --git a/locale/template.txt b/locale/template.txt
index f064a8c..41d1338 100644
--- a/locale/template.txt
+++ b/locale/template.txt
@@ -1,2 +1,5 @@
 # textdomain: mesecons_clock
+On time (seconds)=
+Off time (seconds)=
+Save=
 Mesecons Clock=