diff --git a/home-manager/opdavies/PW05CH3L.nix b/home-manager/opdavies/PW05CH3L.nix
index 55e0f55b..9d511468 100644
--- a/home-manager/opdavies/PW05CH3L.nix
+++ b/home-manager/opdavies/PW05CH3L.nix
@@ -40,6 +40,7 @@
   home.packages = with pkgs; [
     create-script
     tag-release
+    time-until
     todos-add
     update-all-git-repos
   ];
diff --git a/home-manager/opdavies/t480.nix b/home-manager/opdavies/t480.nix
index 6c541251..b1a96869 100644
--- a/home-manager/opdavies/t480.nix
+++ b/home-manager/opdavies/t480.nix
@@ -106,6 +106,7 @@
     move-firefox-screenshots
     setbg
     tag-release
+    time-until
     timer
     todos-add
     unmounter
diff --git a/packages/default.nix b/packages/default.nix
index 42aa2aca..c9ee6d47 100644
--- a/packages/default.nix
+++ b/packages/default.nix
@@ -18,6 +18,7 @@ in
   passmenu-otp = callPackage ./passmenu-otp.nix { };
   setbg = callPackage ./setbg.nix { };
   tag-release = callPackage ./tag-release.nix { };
+  time-until = callPackage ./time-until.nix { };
   timer = callPackage ./timer.nix { };
   tmux-sessionizer = callPackage ./tmux-sessionizer { };
   todos-add = callPackage ./todos-add.nix { };
diff --git a/packages/time-until.nix b/packages/time-until.nix
new file mode 100644
index 00000000..82e1c821
--- /dev/null
+++ b/packages/time-until.nix
@@ -0,0 +1,27 @@
+{ pkgs }:
+
+pkgs.writeShellApplication {
+  name = "time-until";
+
+  runtimeInputs = with pkgs; [ bc ];
+
+  text = ''
+    # Based on https://github.com/sdaschner/dotfiles/blob/master/bin/time-until.
+    set +o nounset
+
+    if [[ "$1" == "" ]]; then
+      echo "Usage: ''${0##*/} <date-string>"
+      echo " Example: ''${0##*/} 'tomorrow 06:00'"
+      exit 2
+    fi
+
+    set -o nounset
+
+    secsUntil=$(( $(date +%s -d "$*") - $( date +%s ) ))
+    minutesUntil=$(bc <<< "scale=1; $secsUntil/60")
+    hoursUntil=$(bc <<< "scale=2; $secsUntil/3600")
+    date=$(date -d "$*")
+
+    echo "$hoursUntil hours (or $minutesUntil mins) until $date"
+  '';
+}