Jesssullivan · Jesssullivan · Jun 11, 2026 · Jun 11, 2026
@@ -66,7 +66,7 @@ never occluded, at every breakpoint.
   lead value** → support sections (full weight) → "More — N sections ▾"
   (collapsed-but-obvious, full contrast) → TOOLS. Deep tools open **inside this
   column** (master-detail) or shrink the stage — never as a `bottom:0 z12` sheet.
-- **DOCK** (bottom, full width): the twilight gantt as its **own reserved row** at
+- **DOCK** (bottom, full width): the time helix (the twilight strip — `TimeHelix.svelte`, née the twilight gantt; the row keeps its `.gantt` smoke contract) as its **own reserved row** at
   every breakpoint — so "X floats over the twilight strip" is structurally
   impossible. Deletes the ~120 lines of `--field-panel-*` math + `!important`
   overrides + the portrait clearance special-case.
@@ -110,7 +110,7 @@ pre-fills the deep tool with `{lat,lon,et,lens,layers,boresight,horizon}` with z
 re-entry. Hover-to-**peek** (ephemeral), click-to-**pin** (commit + enable CTAs);
 value + its one CTA share one large target (Fitts).
 
-- ◐ **Sky** "dark window here" — **≤1 click** (hover=0): inspector leads Bortle + tonight's dark-window inline; full gantt always in the DOCK.
+- ◐ **Sky** "dark window here" — **≤1 click** (hover=0): inspector leads Bortle + tonight's dark-window inline; the full time helix always in the DOCK.
 - ☁ **Air** "AQI here" — **≤1 click**: smog field present on Air-lens entry; inspector leads driving pollutant + NowCast-labeled AQI; AQ summary docked in-inspector.
 - 📡 **Links** "link margin" — **≤2 clicks**: click → path-AOD→T→dB line; "Design a link" → boresight + Tx/Rx + loss breakdown expand *into* the inspector.
 - 🛰 **Orbit** "next pass" — **≤2 clicks**: next DEM-gated pass on pin regardless of lens; "Plan a pass" → polar az/el track + pass list expand in-inspector.

@@ -88,12 +88,15 @@ html {
 	html {
 		--field-bottom-reserve: 8.75rem;
 		--map-toolbar-inset-rem: 5rem;
-		/* The mobile twilight gantt is ~200px tall — taller than --field-bottom-reserve
-		   (8.75rem ≈ 140px), so a tall readout-only state would dip ~60px into it
-		   (TIN-1810). The readout-only portrait rule clears the gantt by anchoring its
-		   bottom at this reserve instead; the gantt/attribution/toolbar keep
-		   --field-bottom-reserve. Tuned against real-font render (the GF cell is
-		   fontless so the overlap never shows in CI). */
+		/* TIN-1810 (gantt era): the old mobile twilight gantt was ~200px tall —
+		   taller than --field-bottom-reserve (8.75rem ≈ 140px) — so a tall
+		   readout-only state dipped ~60px into it. The readout-only portrait rule
+		   clears the strip by anchoring its bottom at this reserve instead; the
+		   strip/attribution/toolbar keep --field-bottom-reserve. The TimeHelix
+		   strip is ~100px (comfortably inside the reserve) but the rule stays —
+		   it is the structural guarantee, not a height tweak. Tuned against
+		   real-font render (the GF cell is fontless so the overlap never shows
+		   in CI). */
 		--gantt-reserve-rem: 13rem;
 	}
 }
@@ -406,7 +409,7 @@ pre.shiki span {
    owns layout. Five named, non-overlapping regions —
    'header header header' / 'rail stage inspector' / 'dock dock dock',
    tracks [20rem][1fr][22rem] — so overlap is impossible by construction: the
-   map (grid-area:stage) + the twilight gantt (its own DOCK row) can only be
+   map (grid-area:stage) + the time helix (its own DOCK row) can only be
    SHRUNK, never occluded. The old z4→z13 ladder + the `.field-hud` scrim are
    deleted; the surfaces flow into grid cells. The only remaining fixed/absolute
    overlays clip to the STAGE cell (toolbar, sky compass, deep-tool sheets,
@@ -420,7 +423,7 @@ pre.shiki span {
      ───────  ───────────────────  ─────────────────────────────
        5      attribution          bottom-left
        6      SkyCompass           top-right (hidden ≤560px)
-       6      EphemerisGantt strip bottom, full width (minus toolbar inset)
+       6      TimeHelix strip     bottom, full width (minus toolbar inset)
        8      MapToolbar           bottom-right
        8      MapErrorToast        bottom-left
        9      LayerRail backdrop   full (mobile drawer only)

@@ -3,7 +3,7 @@
  *
  * Field users need to glance at the map and tell whether a given
  * overlay is showing fresh data, cached data, stale data, or nothing
- * at all. The bottom rail in `EphemerisGantt.svelte` already grew a
+ * at all. The old `EphemerisGantt.svelte` bottom rail grew a
  * one-off `RangeBadge` for the twilight viewport-summary; this module
  * generalizes the same idea into a reusable contract so every overlay
  * surface — LayerRail health pills, future per-overlay chips, the
@@ -47,7 +47,8 @@ export interface CacheBadgeInputs {
 
 /**
  * Human "… ago" string for a stored/computed timestamp. Exported so the
- * EphemerisGantt viewport-summary pill (which this module generalizes) shares
+ * twilight viewport-summary pill (the old EphemerisGantt surface this
+ * module generalizes; deferred in TimeHelix V1) shares
  * one age formatter — including the >24h day rollover — instead of its own copy.
  */
 export const fmtAge = (storedAtMs: number, nowMs: number): string => {
@@ -136,8 +137,9 @@ export const buildCacheBadge = (inputs: CacheBadgeInputs, nowMs: number = Date.n
 };
 
 /**
- * Map a `CacheBadgeTone` to the `.cache-pill` modifier classes used by
- * `EphemerisGantt.svelte`. Exported so a Svelte component can apply
+ * Map a `CacheBadgeTone` to the `.cache-pill` modifier classes the old
+ * `EphemerisGantt.svelte` wore (no consumer while TimeHelix V1 defers the
+ * cache pill). Exported so a Svelte component can apply
  * the right tonal class without re-typing the union.
  */
 export const cachePillToneClass = (tone: CacheBadgeTone): string => `cache-pill-${tone}`;
@@ -2,7 +2,8 @@
 	/**
 	 * MapToolbar — vertical stack of map-overlay toggles in the
 	 * bottom-right corner. Replaces the two standalone time / sun-moon
-	 * buttons that fought the EphemerisGantt + TimeDock for the same space.
+	 * buttons that fought the twilight strip (now TimeHelix) + TimeDock for
+	 * the same space.
 	 *
 	 * The toolbar publishes its width via the `--toolbar-w-rem` CSS
 	 * custom property on `:host`. The gantt + dock read that variable

@@ -229,7 +229,7 @@
      with PEEK / HALF / FULL detents (CSS scroll-snap). The map de-fixes into the
      stage behind it (a map strip is ALWAYS visible at the top — FULL ≈ 88vh, never
      100%). A [Layers · Readout · Tools] segmented control SWAPS the single sheet's
-     content; switching never spawns a 2nd panel. The twilight gantt is a thin
+     content; switching never spawns a 2nd panel. The time helix is a thin
      always-present row ABOVE the sheet peek at every detent. Marked
      .responsive-dock + data-responsive-dock so W4a's tolerant HUD-overlap assertion
      keys off it. -->
@@ -264,7 +264,7 @@
 				<div class="dock-lens-row">{@render lensStrip()}</div>
 			{/if}
 
-			<!-- The twilight gantt: its OWN thin row, always present above everything
+			<!-- The time helix: its OWN thin row, always present above everything
 			     else in the sheet, at every detent. -->
 			{#if ganttRow}
 				<div class="dock-gantt-row">{@render ganttRow()}</div>
@@ -437,7 +437,7 @@
 	}
 
 	/* The gantt's OWN thin row, pinned above the tabs + body — always present. The
-	   EphemerisGantt's COMPACT default is position:fixed at the viewport bottom; here
+	   TimeHelix's COMPACT default is position:fixed at the viewport bottom; here
 	   it must flow inside the sheet as a thin row, so de-float it (it keeps its
 	   .gantt class + aria-label — only positioning changes). */
 	.dock-gantt-row {

@@ -441,7 +441,7 @@
 			{:else if moonHorizonDelta}
 				<span class="horizon">h {fmtAlt(moonHorizonDelta.horizonAlt)}</span>
 			{/if}
-			<!-- Moon phase/illumination is shown once, in the EphemerisGantt readout
+			<!-- Moon phase/illumination is shown once, in the TimeHelix moon chip
 			     rendered alongside this compass; the compass row keeps the
 			     position-specific alt/az/horizon and omits the duplicate phase. -->
 		</div>

@@ -3,7 +3,7 @@
  *
  * Flat-horizon sunrise = the instant the sun's geocentric altitude
  * crosses 0°. That's what astronomy-engine's `SearchAltitude` /
- * `SearchRiseSet` return — and it's what the EphemerisGantt shows
+ * `SearchRiseSet` return — and it's what the TimeHelix shows
  * today. For dark-sky / spectroscopy field work the answer that
  * actually matters is the instant the sun crosses the *local*
  * horizon at its azimuth, which is what a HorizonPolygon encodes.

@@ -29,8 +29,8 @@ export interface PhaseDefinition {
 
 /**
  * Canonical phase table. Colors mirror the Photographer's Ephemeris
- * palette previously inlined in `EphemerisGantt.svelte` so the visual
- * appearance does not change.
+ * palette inlined in the old `EphemerisGantt.svelte` (the TimeHelix ribbon
+ * consumes it now) so the visual appearance does not change.
  */
 export const PHASE_DEFINITIONS: Readonly<Record<PhaseName, PhaseDefinition>> = {
 	night: {

@@ -1,7 +1,8 @@
 /**
  * Viewport sampling helpers.
  *
- * The EphemerisGantt's per-event range pill samples ephemeris at a
+ * The twilight viewport-summary (born as the EphemerisGantt's range
+ * pill; its TimeHelix successor defers the pill UI) samples ephemeris at a
  * 4×4 grid of points inside the visible viewport. The math is in a
  * pure helper here so it can be unit-tested independently from the
  * Svelte component — which matters because the bug it fixes (silent
@@ -28,7 +29,7 @@ const canonicalizeLon = (lon: number): number => ((((lon + 180) % 360) + 360) %
  * Returns the empty array for degenerate viewports (zero or negative
  * span on either axis).
  *
- * Caller picks N (the EphemerisGantt uses 4 for ephemeris range
+ * Caller picks N (the viewport summary uses 4 for ephemeris range
  * sampling — 16 calls is cheap and covers the variability that
  * matters for state-scale viewports).
  */

@@ -267,7 +267,7 @@
 			{
 				anchor: '[data-tour="toolbar"]',
 				title: 'Twilight & ephemeris',
-				body: 'Open the twilight gantt for sun/moon timing and the sky compass — plan the session around the dark hours.',
+				body: 'Open the time helix for sun/moon timing and the sky compass — now sits at the center; drag the ribbon to plan the session around the dark hours.',
 			},
 		],
 		// Air (weather/smog): atmosphere overlays + PM2.5 field, NowCast vs 24-h, AQ tools.
@@ -436,7 +436,7 @@
 		{
 			id: 'tool-twilight',
 			label: 'Toggle Twilight strip',
-			keywords: 'sun moon timing dark window ephemeris gantt',
+			keywords: 'sun moon timing dark window ephemeris gantt time helix',
 			run: () => (ephemerisOpen = !ephemerisOpen),
 		},
 		{
@@ -2759,7 +2759,7 @@
 		{/if}
 	</aside>
 
-	<!-- DOCK region: the twilight gantt as its OWN reserved bottom row at WIDE — so
+	<!-- DOCK region: the time helix as its OWN reserved bottom row at WIDE — so
 	     "X floats over the twilight strip" is structurally impossible. ≤1023px
 	     display:contents → the gantt keeps its current fixed bottom-strip layout.
 	     W4c — at COMPACT-tall the gantt is the dock sheet's thin top row instead. -->
@@ -3311,7 +3311,7 @@
 		}
 
 		/* De-fix the region children at MEDIUM+WIDE: the lens chips + geocoder
-		   (HEADER), the PointReadout (INSPECTOR), and the twilight gantt (DOCK) drop
+		   (HEADER), the PointReadout (INSPECTOR), and the time helix (DOCK) drop
 		   their own position:fixed/inset/z-index and flow into their grid cells. Their
 		   own <640px float positioning is untouched (the COMPACT fallback). The stage
 		   overlays (toolbar, sky, sheets) stay fixed at COMPACT; here they clip to the

@@ -23,7 +23,7 @@
 			persona: 'Astro instrumentation & astrophotography',
 			question: 'When and where is tonight dark, clear, and steady enough for my target?',
 			tools:
-				'VIIRS + Falchi radiance → Bortle / SQM · ephemeris & twilight gantt · SkyCompass · DEM horizon · T(λ) extinction',
+				'VIIRS + Falchi radiance → Bortle / SQM · ephemeris & time helix · SkyCompass · DEM horizon · T(λ) extinction',
 			cta: 'Open the Sky lens',
 		},
 		{
@@ -121,8 +121,8 @@
 		</p>
 		<ul class="mb-3 list-disc space-y-1 pl-6">
 			<li>
-				<strong>◐ Sky</strong> — astronomers &amp; astrophotographers: VIIRS + Falchi radiance → Bortle / SQM, the twilight
-				gantt + sky compass, and the real DEM horizon for a dark-sky site.
+				<strong>◐ Sky</strong> — astronomers &amp; astrophotographers: VIIRS + Falchi radiance → Bortle / SQM, the time helix
+				+ sky compass, and the real DEM horizon for a dark-sky site.
 			</li>
 			<li>
 				<strong>☁ Air</strong> — weather, pollen &amp; smog analysts: GIBS cloud / aerosol / water-vapor overlays plus a modeled
@@ -164,8 +164,8 @@
 				readout (with Bortle / class mapping)
 			</li>
 			<li>
-				<strong>Per-view ephemeris</strong> — sun + moon position, twilight gantt (astro / nautical / civil), sky compass
-				with sun trajectory arc + moon position + atmospheric airmass
+				<strong>Per-view ephemeris</strong> — sun + moon position, the now-centered time helix (astro / nautical / civil twilight),
+				sky compass with sun trajectory arc + moon position + atmospheric airmass
 			</li>
 			<li>
 				<strong>Real-terrain horizon</strong> — 36-ray, 10-distance raycast over AWS Mapzen Terrarium tiles; sun / moon altitude