{
  "schema_version": "1.0.0",
  "license": "CC0-1.0",
  "docs": "https://mike.quarterly.systems/llms.txt",
  "generated_at": "2026-08-07T03:37:41.702Z",
  "commit": "4e33f3cd812109539f1d1b34dd614bb3c35a5c26",
  "id": "phi",
  "title": "Personal Health Index (PHI)",
  "unit": "Index (2023-2025 avg = 100)",
  "frequency": "monthly",
  "category": "Health & Wellness",
  "source": "Apple Watch / Apple Health (via Health Auto Export)",
  "calculation": "PHI = 0.30·Recovery + 0.25·Sleep + 0.25·Activity + 0.20·Fitness. Each metric's monthly mean is scored vs its 2023-2025 baseline (direction-corrected, capped 60-160); the index is re-based so the 2023-2025 mean = 100. Data begins 2023-01 (Apple Watch sleep-stage tracking availability); rows carry the release-lag date, so the first row is 2023-02. Full method: /reports/phi-2.0-methodology.",
  "baseline": 100,
  "date_convention": "release-lag",
  "vintages": [
    {
      "id": "phi-classic",
      "superseded_on": "2026-07-04",
      "reason": "Rebuilt on Apple Watch recovery/sleep/activity/fitness data (PHI 2.0)",
      "url": "/api/v1/series/phi-classic.json"
    }
  ],
  "observations": [
    {
      "date": "2023-02-01",
      "period": {
        "start": "2023-01-01",
        "end": "2023-01-31"
      },
      "value": 112.4,
      "notes": "Strong month — activity and sleep strong. During an intensive training block."
    },
    {
      "date": "2023-03-01",
      "period": {
        "start": "2023-02-01",
        "end": "2023-02-28"
      },
      "value": 103.5,
      "notes": "Near baseline — activity strong; fitness soft. During an intensive training block."
    },
    {
      "date": "2023-04-01",
      "period": {
        "start": "2023-03-01",
        "end": "2023-03-31"
      },
      "value": 106.6,
      "notes": "Near baseline — activity and sleep strong."
    },
    {
      "date": "2023-05-01",
      "period": {
        "start": "2023-04-01",
        "end": "2023-04-30"
      },
      "value": 101.8,
      "notes": "Near baseline — sleep strong."
    },
    {
      "date": "2023-06-01",
      "period": {
        "start": "2023-05-01",
        "end": "2023-05-31"
      },
      "value": 101.9,
      "notes": "Near baseline — sleep strong."
    },
    {
      "date": "2023-07-01",
      "period": {
        "start": "2023-06-01",
        "end": "2023-06-30"
      },
      "value": 103.4,
      "notes": "Near baseline — sleep strong."
    },
    {
      "date": "2023-08-01",
      "period": {
        "start": "2023-07-01",
        "end": "2023-07-31"
      },
      "value": 111.1,
      "notes": "Strong month — activity strong."
    },
    {
      "date": "2023-09-01",
      "period": {
        "start": "2023-08-01",
        "end": "2023-08-31"
      },
      "value": 96.2,
      "notes": "Near baseline — fitness strong; activity soft."
    },
    {
      "date": "2023-10-01",
      "period": {
        "start": "2023-09-01",
        "end": "2023-09-30"
      },
      "value": 98.6,
      "notes": "Near baseline — steady across pillars."
    },
    {
      "date": "2023-11-01",
      "period": {
        "start": "2023-10-01",
        "end": "2023-10-31"
      },
      "value": 107.3,
      "notes": "Strong month — activity and sleep strong."
    },
    {
      "date": "2023-12-01",
      "period": {
        "start": "2023-11-01",
        "end": "2023-11-30"
      },
      "value": 86.9,
      "notes": "Soft month — activity floored; fitness soft. Holiday season."
    },
    {
      "date": "2024-01-01",
      "period": {
        "start": "2023-12-01",
        "end": "2023-12-31"
      },
      "value": 98.3,
      "notes": "Near baseline — sleep strong; activity and fitness soft. Holiday season."
    },
    {
      "date": "2024-02-01",
      "period": {
        "start": "2024-01-01",
        "end": "2024-01-31"
      },
      "value": 104.1,
      "notes": "Near baseline — sleep strong; fitness soft. New-year reset."
    },
    {
      "date": "2024-03-01",
      "period": {
        "start": "2024-02-01",
        "end": "2024-02-29"
      },
      "value": 108.2,
      "notes": "Strong month — sleep and recovery strong."
    },
    {
      "date": "2024-04-01",
      "period": {
        "start": "2024-03-01",
        "end": "2024-03-31"
      },
      "value": 109.1,
      "notes": "Strong month — activity strong; sleep and fitness soft."
    },
    {
      "date": "2024-05-01",
      "period": {
        "start": "2024-04-01",
        "end": "2024-04-30"
      },
      "value": 100.7,
      "notes": "Near baseline — steady across pillars."
    },
    {
      "date": "2024-06-01",
      "period": {
        "start": "2024-05-01",
        "end": "2024-05-31"
      },
      "value": 101.4,
      "notes": "Near baseline — steady across pillars."
    },
    {
      "date": "2024-07-01",
      "period": {
        "start": "2024-06-01",
        "end": "2024-06-30"
      },
      "value": 99.5,
      "notes": "Near baseline — recovery strong; sleep soft."
    },
    {
      "date": "2024-08-01",
      "period": {
        "start": "2024-07-01",
        "end": "2024-07-31"
      },
      "value": 100.7,
      "notes": "Near baseline — recovery strong; sleep soft."
    },
    {
      "date": "2024-09-01",
      "period": {
        "start": "2024-08-01",
        "end": "2024-08-31"
      },
      "value": 110.6,
      "notes": "Strong month — activity and recovery strong."
    },
    {
      "date": "2024-10-01",
      "period": {
        "start": "2024-09-01",
        "end": "2024-09-30"
      },
      "value": 96,
      "notes": "Near baseline — activity soft."
    },
    {
      "date": "2024-11-01",
      "period": {
        "start": "2024-10-01",
        "end": "2024-10-31"
      },
      "value": 102.1,
      "notes": "Near baseline — sleep strong."
    },
    {
      "date": "2024-12-01",
      "period": {
        "start": "2024-11-01",
        "end": "2024-11-30"
      },
      "value": 96.4,
      "notes": "Near baseline — fitness strong; activity soft."
    },
    {
      "date": "2025-01-01",
      "period": {
        "start": "2024-12-01",
        "end": "2024-12-31"
      },
      "value": 97.2,
      "notes": "Near baseline — fitness strong; activity floored. Holiday season."
    },
    {
      "date": "2025-02-01",
      "period": {
        "start": "2025-01-01",
        "end": "2025-01-31"
      },
      "value": 95,
      "notes": "Near baseline — activity soft."
    },
    {
      "date": "2025-03-01",
      "period": {
        "start": "2025-02-01",
        "end": "2025-02-28"
      },
      "value": 100.4,
      "notes": "Near baseline — steady across pillars."
    },
    {
      "date": "2025-04-01",
      "period": {
        "start": "2025-03-01",
        "end": "2025-03-31"
      },
      "value": 99.2,
      "notes": "Near baseline — steady across pillars."
    },
    {
      "date": "2025-05-01",
      "period": {
        "start": "2025-04-01",
        "end": "2025-04-30"
      },
      "value": 104.6,
      "notes": "Near baseline — activity and sleep strong."
    },
    {
      "date": "2025-06-01",
      "period": {
        "start": "2025-05-01",
        "end": "2025-05-31"
      },
      "value": 111.7,
      "notes": "Strong month — activity and recovery strong."
    },
    {
      "date": "2025-07-01",
      "period": {
        "start": "2025-06-01",
        "end": "2025-06-30"
      },
      "value": 93.1,
      "notes": "Soft month — sleep soft."
    },
    {
      "date": "2025-08-01",
      "period": {
        "start": "2025-07-01",
        "end": "2025-07-31"
      },
      "value": 97.9,
      "notes": "Near baseline — sleep strong; activity soft."
    },
    {
      "date": "2025-09-01",
      "period": {
        "start": "2025-08-01",
        "end": "2025-08-31"
      },
      "value": 97.6,
      "notes": "Near baseline — fitness strong; sleep and recovery soft."
    },
    {
      "date": "2025-10-01",
      "period": {
        "start": "2025-09-01",
        "end": "2025-09-30"
      },
      "value": 84.8,
      "notes": "Soft month — activity floored; sleep soft. Amid relocation upheaval."
    },
    {
      "date": "2025-11-01",
      "period": {
        "start": "2025-10-01",
        "end": "2025-10-31"
      },
      "value": 85.8,
      "notes": "Soft month — activity floored; fitness soft. Amid relocation upheaval."
    },
    {
      "date": "2025-12-01",
      "period": {
        "start": "2025-11-01",
        "end": "2025-11-30"
      },
      "value": 85.5,
      "notes": "Soft month — activity and sleep soft. Relocation upheaval and a high-stress stretch."
    },
    {
      "date": "2026-01-01",
      "period": {
        "start": "2025-12-01",
        "end": "2025-12-31"
      },
      "value": 90.7,
      "notes": "Soft month — activity floored; fitness soft. Holidays; moving into a new home."
    },
    {
      "date": "2026-02-01",
      "period": {
        "start": "2026-01-01",
        "end": "2026-01-31"
      },
      "value": 91.2,
      "notes": "Soft month — activity floored; sleep soft. New year; settling into a new home."
    },
    {
      "date": "2026-03-01",
      "period": {
        "start": "2026-02-01",
        "end": "2026-02-28"
      },
      "value": 102.7,
      "notes": "Near baseline — recovery strong. A nomadic stretch between cities."
    },
    {
      "date": "2026-04-01",
      "period": {
        "start": "2026-03-01",
        "end": "2026-03-31"
      },
      "value": 102.6,
      "notes": "Near baseline — fitness and recovery strong. Based in Koreatown, LA."
    },
    {
      "date": "2026-05-01",
      "period": {
        "start": "2026-04-01",
        "end": "2026-04-30"
      },
      "value": 101.6,
      "notes": "Near baseline — fitness and recovery strong; sleep soft. Based in Koreatown, LA."
    },
    {
      "date": "2026-06-01",
      "period": {
        "start": "2026-05-01",
        "end": "2026-05-31"
      },
      "value": 113.2,
      "notes": "Strong month — activity and recovery strong; sleep soft. Living in Kosovo."
    },
    {
      "date": "2026-07-01",
      "period": {
        "start": "2026-06-01",
        "end": "2026-06-30"
      },
      "value": 106,
      "notes": "Near baseline — recovery and activity strong; sleep soft. Living in Kosovo."
    },
    {
      "date": "2026-08-01",
      "period": {
        "start": "2026-07-01",
        "end": "2026-07-31"
      },
      "value": 111.6,
      "notes": "Strong month: activity strong. Portland, with 25 rides and steps 48% above baseline. Cycling stopped July 26 with the move to Oakland, CA."
    }
  ]
}