gnu: Add ktimer.

* gnu/packages/kde.scm (ktimer): New variable.

gnu/packages/kde.scm

@@ -898,6 +898,33 @@ (define-public kdf
 partitions, floppy and CD drives, etc.) along with information on their
 capacity, free space, type and mount point.  It also allows you to mount and
 unmount drives and view them in a file manager.")
+(license license:gpl2+)))
+
+(define-public ktimer
+  (package
+    (name "ktimer")
+    (version "20.12.0")
+    (source (origin
+              (method url-fetch)
+              (uri (string-append "mirror://kde/stable/release-service/" version
+                                  "/src/ktimer-" version ".tar.xz"))
+              (sha256
+               (base32
+                "12fz5v5ky03h18jl75fnq1zagjq8qzi1s1q7phjz5d1rbhwc57ls"))))
+    (build-system qt-build-system)
+    (native-inputs
+     (list extra-cmake-modules
+           kdoctools))
+    (inputs
+     (list kdbusaddons
+           ki18n
+           kio
+           knotifications))
+    (home-page "https://kde.org/applications/utilities/ktimer")
+    (synopsis "Countdown Launcher")
+    (description "KTimer is a little tool to execute programs after some time.
+It allows you to enter several tasks and to set a timer for each of them.  The
+timers for each task can be started, stopped, changed, or looped.")
     (license license:gpl2+)))
 
 (define-public kcachegrind