fix: derive upcoming fixture day label from computed local kickoff time

Previously used the stored venue date for Today/Tomorrow logic, which
gave wrong results when the UTC kickoff crossed midnight into the next
local day (e.g. 18:00 UTC-7 = 01:00 UTC next day). Now computes UTC
kickoff first, converts to the viewer's local time, and derives the
day label from that local Date object.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/page.tsx

@@ -57,26 +57,30 @@ function formatKickoff(date: string | null | undefined, time: string | null | un
   if (!date) return ''
   const today = new Date()
   const tomorrow = new Date(today); tomorrow.setDate(today.getDate() + 1)
+
+  if (time) {
+    const m = time.match(/^(\d{2}):(\d{2})(?:\s+UTC([+-]\d+(?:\.\d+)?))?/)
+    if (m) {
+      const [y, mo, d] = date.split('-').map(Number)
+      const h = parseInt(m[1]), min = parseInt(m[2])
+      const offsetH = m[3] ? parseFloat(m[3]) : 0
+      // Compute UTC kickoff, then let the browser render in its local timezone
+      const local = new Date(Date.UTC(y, mo - 1, d, h - offsetH, min))
+      const isToday = local.toDateString() === today.toDateString()
+      const isTomorrow = local.toDateString() === tomorrow.toDateString()
+      const dayLabel = isToday ? 'Today' : isTomorrow ? 'Tomorrow'
+        : local.toLocaleDateString('en-GB', { weekday: 'short', day: 'numeric', month: 'short' })
+      const localTime = local.toLocaleTimeString('en-GB', { hour: '2-digit', minute: '2-digit' })
+      return `${dayLabel} · ${localTime}`
+    }
+  }
+
+  // No time — fall back to venue date label only
   const matchDate = new Date(date + 'T00:00:00')
   const isToday = matchDate.toDateString() === today.toDateString()
   const isTomorrow = matchDate.toDateString() === tomorrow.toDateString()
-  const dayLabel = isToday ? 'Today' : isTomorrow ? 'Tomorrow'
+  return isToday ? 'Today' : isTomorrow ? 'Tomorrow'
     : matchDate.toLocaleDateString('en-GB', { weekday: 'short', day: 'numeric', month: 'short' })
-
-  if (!time) return dayLabel
-
-  // Parse "HH:MM UTC±N" and convert to viewer's local time
-  const m = time.match(/^(\d{2}):(\d{2})(?:\s+UTC([+-]\d+(?:\.\d+)?))?/)
-  if (!m) return dayLabel
-  const h = parseInt(m[1]), min = parseInt(m[2])
-  const offsetH = m[3] ? parseFloat(m[3]) : 0
-  const utcMs = Date.UTC(
-    matchDate.getFullYear(), matchDate.getMonth(), matchDate.getDate(),
-    h - offsetH, min
-  )
-  const local = new Date(utcMs)
-  const localTime = local.toLocaleTimeString('en-GB', { hour: '2-digit', minute: '2-digit' })
-  return `${dayLabel} · ${localTime}`
 }
 
 function UpcomingFixture({ match }: { match: UpcomingMatch }) {