diff --git a/agent/BACKLOG.md b/agent/BACKLOG.md
index 91a4e90..fe27dd0 100644
--- a/agent/BACKLOG.md
+++ b/agent/BACKLOG.md
@@ -252,55 +252,6 @@ Next slice: on hardware, run `hyprctl clients` while each is open, read
 the real `class`, then append rules. Also revisit whether blueman/s-c-p
 actually float once seen (regex tolerance for the `.…-wrapped` form).
 
-### 42. System calendar app synced to the user's accounts `[big]`
-(Raised by Bernardo, 2026-07-08.) Clicking the Waybar **date/clock**
-module should open a calendar that shows the user's real events, synced
-from their calendar accounts (CalDAV / Google / Nextcloud / iCloud). Hard
-requirement: it must open **instantly** on click — no Thunderbird/Evolution
-multi-second cold start.
-
-_Investigation (2026-07-08 — Bernardo suggested calcurse; asked for the
-best approach):_ the winning shape is **split sync from display** — a sync
-daemon fills a local store, a fast local viewer reads it instantly.
-- **Recommended (most Nomarchy-native): `khal` (TUI) in a floating ghostty
-  window + `vdirsyncer` for sync.** khal reads a local vdir instantly →
-  opens immediately; running it in ghostty means it **themes for free** off
-  the palette (pillar 4, zero new theming surface) and slots into the
-  float+center windowrule pattern (item 41). vdirsyncer is the de-facto
-  CalDAV→local-ics sync (Nextcloud/Fastmail/iCloud with an app password are
-  frictionless). Configs are file-based → in-flake friendly.
-- **calcurse (Bernardo's pick):** viable, instant TUI, single self-contained
-  tool — but it's *local-first*; `calcurse-caldav` multi-account/Google sync
-  is clunkier than vdirsyncer. Fine if a one-tool solution is preferred over
-  sync robustness.
-- **GNOME Calendar + GNOME Online Accounts:** the GUI path with the *best*
-  Google onboarding (GOA handles OAuth cleanly), themes via GTK — but it's
-  heavier and pulls evolution-data-server + GOA, and first-open is **not
-  instant**, so it fails the core requirement. Fallback only if easy account
-  setup outweighs instant-open. (`gcalcli` = Google-only, not general.)
-
-_Two real wrinkles to design around:_
-1. **Credentials are secrets** — account passwords / OAuth tokens can't live
-   in the git-tracked flake, so this is the one legitimate exception to
-   "no state outside the checkout" (see [[in-flake-state-philosophy]]).
-   Decide: a plain runtime path (`~/.config`, documented exception) vs
-   sops/agenix encrypted-in-flake.
-2. **Google OAuth friction** — vdirsyncer needs a *self-registered*
-   `client_id`/`client_secret` (shipping one violates Google ToS). CalDAV
-   app-password providers are painless; Google is the sharp edge. GOA
-   sidesteps it but only on the heavy GUI path.
-
-_Slices (split before starting):_ (a) `[human]` pick the tool
-(recommend khal+vdirsyncer; calcurse acceptable), then ship the viewer
-bound to the clock `on-click` — launch it in a ghostty window with a
-distinct `--class` so a float+center windowrule can target it; move the
-current time↔date `format-alt` toggle to `on-click-right`/scroll; parity
-across the four whole-swap jsoncs. Local-only first (an .ics on disk).
-(b) add vdirsyncer + a sync systemd timer (like the update checker) + a
-menu writer for accounts, resolving the secrets decision above. (c) optional
-polish: upcoming events in the clock **tooltip** via a khal-backed script
-(hover = next events, click = full calendar).
-
 ## LATER
 
 - **Wallpapers artifact split** (ROADMAP § Faster switches — decided,
diff --git a/agent/HARDWARE-QUEUE.md b/agent/HARDWARE-QUEUE.md
index a0fe1ca..85a4008 100644
--- a/agent/HARDWARE-QUEUE.md
+++ b/agent/HARDWARE-QUEUE.md
@@ -293,6 +293,17 @@ QA machine), the **T14s** (webcam case).
       night, executive-slate, boreal) behave the same and their shutdown
       power-button (if present) still opens the lock/logout menu.
 
+- [ ] **Calendar on the clock click** (iteration #68, item 42) — after
+      `home-update` + relogin: left-click the Waybar date/clock → calcurse
+      opens in a **floating, centered** ghostty window (~60×65% of screen),
+      showing the month calendar; closing calcurse (`q`) closes the window.
+      The `--class=com.nomarchy.calendar` must match the windowrule (if it
+      tiles, run `hyprctl clients` while open and check the real app-id).
+      Hover the clock → tooltip shows the long date + zone + month grid.
+      Same on a whole-swap bar (summer/boreal/executive-slate). If calcurse
+      was removed from home.packages, the click toasts "calcurse isn't
+      installed" instead of doing nothing.
+
 ## AMD dev box only
 - [ ] **AMD runtime bits** — VA-API (`vainfo` → radeonsi), amd-pstate EPP
       active and PPD switching governors; opt-ins: ROCm (`rocminfo`, a GPU
diff --git a/agent/JOURNAL.md b/agent/JOURNAL.md
index 89e4d63..d36b573 100644
--- a/agent/JOURNAL.md
+++ b/agent/JOURNAL.md
@@ -17,6 +17,35 @@ Template:
 
 ---
 
+## 2026-07-08 — Calendar on the clock click (iteration #68, item 42)
+- **Task:** item 42, de-scoped live by Bernardo — DON'T hook up calendar
+  accounts; just ship a lightweight calendar that opens instantly on the
+  Waybar date click, user configures sync themselves. calcurse (his pick;
+  now the right one since it's self-contained for the user's own sync).
+- **Did:** new `nomarchy-calendar` launcher (waybar.nix) → calcurse in a
+  ghostty window tagged `--class=com.nomarchy.calendar` +
+  `--gtk-single-instance=false` (fresh standalone window); self-gates on
+  calcurse. Clock `on-click = nomarchy-calendar`, dropped the format-alt
+  date-toggle (conflicts with on-click), moved the long date into the
+  tooltip. Parity: on-click in all four whole-swap jsoncs. windowrule
+  float+size(60/65%)+center on the class (hyprland.nix). Shipped calcurse
+  + pwvucontrol **uncommented** in the downstream template (opt-out).
+  Enforced **ghostty always installed** (ghostty.nix: `enable = true`
+  unconditional, the nomarchy.ghostty.enable option now gates only config)
+  so the launcher can rely on `--class`.
+- **Verified:** V0 green; all four jsoncs valid JSON; V1 HM built — launcher
+  ships the right command, generated clock renders `on-click:
+  nomarchy-calendar` with format-alt gone + date in the tooltip, hyprland
+  has the 3 calendar windowrules, ghostty present in the HM profile.
+- **Pending:** V3 — click the clock → calcurse floats centered (the
+  `--class`→windowrule match) and renders its month view; verify on a real
+  session (queued). Sync is deliberately the user's own local config, NOT
+  a distro feature (Bernardo's call) — a future iteration should not
+  re-propose account sync.
+- **Next suggestion:** Bernardo's big new task — investigate whether THIS
+  machine (NixOS 25.11) can migrate to Nomarchy without a reinstall,
+  keeping all files, and plan it.
+
 ## 2026-07-08 — Combined power menu on the bar icons (iteration #67, item 36b)
 - **Task:** BACKLOG item 36(b), now unblocked. Bernardo's calls: keep the
   granular System ▸ Battery limit / Power profile rows; build ONE combined
diff --git a/modules/home/ghostty.nix b/modules/home/ghostty.nix
index 1c54715..0ed7993 100644
--- a/modules/home/ghostty.nix
+++ b/modules/home/ghostty.nix
@@ -8,11 +8,16 @@ let
   c = t.colors;
 in
 {
-  programs.ghostty = lib.mkIf config.nomarchy.ghostty.enable {
+  # Ghostty is ALWAYS installed — it's Nomarchy's default terminal and is
+  # load-bearing (SUPER+E file manager, the calendar launcher's classed
+  # window, etc.), so the distro enforces it. `nomarchy.ghostty.enable` now
+  # gates only whether Nomarchy's theming/config is applied — a user can
+  # keep ghostty but drop our config, they just can't remove ghostty itself.
+  programs.ghostty = {
     enable = true;
     enableBashIntegration = true;
 
-    settings = {
+    settings = lib.mkIf config.nomarchy.ghostty.enable {
       # ── Typography (from theme-state.json) ────────────────────────
       font-family = t.fonts.mono;
       font-size = t.fonts.size;
diff --git a/modules/home/hyprland.nix b/modules/home/hyprland.nix
index 4d71267..6bb8d44 100644
--- a/modules/home/hyprland.nix
+++ b/modules/home/hyprland.nix
@@ -458,6 +458,13 @@ in
         # Bluetooth manager (blueman) + CUPS printer admin.
         "float, class:(?i)^(\\.?blueman-(manager|adapters)(-wrapped)?|\\.?system-config-printer(-wrapped)?)$"
         "center, class:(?i)^(\\.?blueman-(manager|adapters)(-wrapped)?|\\.?system-config-printer(-wrapped)?)$"
+
+        # Calendar popup (item 42): the Waybar clock's on-click runs
+        # nomarchy-calendar → calcurse in a ghostty window tagged with a
+        # distinct --class, so it floats centered instead of tiling.
+        "float, class:^(com\\.nomarchy\\.calendar)$"
+        "size 60% 65%, class:^(com\\.nomarchy\\.calendar)$"
+        "center, class:^(com\\.nomarchy\\.calendar)$"
       ];
 
       # Rendered from ./keybinds.nix (the cheatsheet reads the same list),
diff --git a/modules/home/waybar.nix b/modules/home/waybar.nix
index 5da16bc..fd4a61b 100644
--- a/modules/home/waybar.nix
+++ b/modules/home/waybar.nix
@@ -82,6 +82,22 @@ let
     [ -n "$next" ] && powerprofilesctl set "$next"
   '';
 
+  # Opens calcurse (a lightweight TUI calendar, month view by default) in a
+  # floating, centered ghostty window — bound to the Waybar clock's on-click.
+  # A distinct --class gives the window a matchable app-id for the
+  # float+center+size windowrule (hyprland.nix); --gtk-single-instance=false
+  # forces a fresh standalone window (ghostty defaults single-instance on).
+  # calcurse ships uncommented in the downstream template (opt-out), so
+  # self-gate with a helpful notify if it's been removed. ghostty is always
+  # installed (ghostty.nix), so it can be relied on for the --class window.
+  calendarLauncher = pkgs.writeShellScriptBin "nomarchy-calendar" ''
+    if ! command -v calcurse >/dev/null 2>&1; then
+      notify-send "Calendar" "calcurse isn't installed (removed from home.packages?)." 2>/dev/null
+      exit 0
+    fi
+    exec ghostty --class=com.nomarchy.calendar --gtk-single-instance=false -e calcurse
+  '';
+
   # VPN indicator — shows a shield when a NetworkManager VPN/WireGuard
   # connection is active OR Tailscale is up; prints nothing otherwise so the
   # module self-hides (like nightlight/updates). Click opens the VPN submenu.
@@ -154,10 +170,13 @@ let
 
     clock = {
       format = "{:%H:%M}";
-      format-alt = "{:%A %d %B %Y}";
-      # Zone line first (LATER nicety): under auto-timezone the tz-watch
-      # SIGUSR2 reload keeps it showing the currently *detected* zone.
-      tooltip-format = "{:%Z (UTC%z)}\n<tt><small>{calendar}</small></tt>";
+      # Left-click → the calendar (nomarchy-calendar → calcurse in a floating
+      # ghostty). Replaces the old format-alt date toggle; the long date now
+      # rides in the tooltip's first line, so nothing is lost on hover.
+      on-click = "nomarchy-calendar";
+      # The zone line stays live under auto-timezone (the tz-watch SIGUSR2
+      # reload keeps it showing the currently *detected* zone).
+      tooltip-format = "{:%A %d %B %Y}\n{:%Z (UTC%z)}\n<tt><small>{calendar}</small></tt>";
     };
 
     # Active keyboard layout (per focused device) — only placed in
@@ -431,5 +450,5 @@ in
   # whole-swap themes' static waybar.jsonc can exec them by name — plus
   # the supervisor hyprland.nix exec-onces.
   home.packages = lib.optionals config.nomarchy.waybar.enable
-    [ waybarSupervisor powerProfileStatus powerProfileCycle vpnStatus doctorStatus ];
+    [ waybarSupervisor powerProfileStatus powerProfileCycle vpnStatus doctorStatus calendarLauncher ];
 }
diff --git a/templates/downstream/home.nix b/templates/downstream/home.nix
index 1eff4db..96e120d 100644
--- a/templates/downstream/home.nix
+++ b/templates/downstream/home.nix
@@ -82,6 +82,7 @@
     mpv                 # media player
     amberol             # music player (local library; streaming → spotify below)
     pwvucontrol         # PipeWire volume mixer (right-click the Waybar volume)
+    calcurse            # TUI calendar — click the Waybar clock to open it
 
     # ── More apps — uncomment to add ─────────────────────────────────
     # Web browsers
diff --git a/themes/boreal/waybar.jsonc b/themes/boreal/waybar.jsonc
index 30c1f05..2c8e8f4 100644
--- a/themes/boreal/waybar.jsonc
+++ b/themes/boreal/waybar.jsonc
@@ -39,6 +39,7 @@
   },
   "clock": {
     "format": "{:%H:%M}",
+    "on-click": "nomarchy-calendar",
     "tooltip": true,
     "tooltip-format": "{:%Z (UTC%z)}\n<tt><small>{calendar}</small></tt>"
   },
diff --git a/themes/executive-slate/waybar.jsonc b/themes/executive-slate/waybar.jsonc
index 40a86db..00cb66b 100644
--- a/themes/executive-slate/waybar.jsonc
+++ b/themes/executive-slate/waybar.jsonc
@@ -46,6 +46,7 @@
   },
   "clock": {
     "format": "{:%H:%M}",
+    "on-click": "nomarchy-calendar",
     "tooltip": true,
     "tooltip-format": "{:%Z (UTC%z)}\n<tt><small>{calendar}</small></tt>"
   },
diff --git a/themes/summer-day/waybar.jsonc b/themes/summer-day/waybar.jsonc
index 6af034f..a9f6d1d 100644
--- a/themes/summer-day/waybar.jsonc
+++ b/themes/summer-day/waybar.jsonc
@@ -70,6 +70,7 @@
 
   "clock": {
     "format": " {:%H:%M}",
+    "on-click": "nomarchy-calendar",
     "tooltip": true,
     "tooltip-format": "{:%Z (UTC%z)}\n<tt><small>{calendar}</small></tt>"
   },
diff --git a/themes/summer-night/waybar.jsonc b/themes/summer-night/waybar.jsonc
index a3ec3e5..9ff5fdf 100644
--- a/themes/summer-night/waybar.jsonc
+++ b/themes/summer-night/waybar.jsonc
@@ -69,6 +69,7 @@
 
   "clock": {
     "format": " {:%H:%M}",
+    "on-click": "nomarchy-calendar",
     "tooltip": true,
     "tooltip-format": "{:%Z (UTC%z)}\n<tt><small>{calendar}</small></tt>"
   },