True Solar Time

True solar time correction and solar-corrected BaZi / Four Pillars casting — historical DST, longitude and equation of time, with hour-branch boundary…

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What it can do

  • True Solar Time: Convert a recorded birth time (wall clock + IANA time zone + longitude) into true solar time — the time a BaZi / Four Pillars chart should actually be cast from. Returns the corrected
  • Hour Branch: Which two-hour branch (子丑寅卯…) a given time falls in, and minutes to the nearest branch boundary. Use on an already-corrected time; for raw birth records use true_solar_time.
  • Cast Pillars: Cast a BaZi / Four Pillars chart the right way round: true solar time correction FIRST, then the four pillars with hidden stems and Na Yin, plus luck cycles. Runs on the production Auspi

What data it sees

Do you need an account

No: the server works without sign-in

True solar time correction and solar-corrected BaZi / Four Pillars casting — historical DST, longitude and equation of time, with hour-branch boundary detection. The step most chart tools skip. Deterministic, no auth, no state.

How to connect

How to connect True Solar Time to Claude

The server address to paste into Claude settings:

https://true-solar-time--shan-liu-s3.run.tools

  1. Open Claude (claude.ai or the desktop app).
  2. Go to Settings → Connectors.
  3. Click Add custom connector.
  4. Paste the server address copied below into Remote MCP server URL and click Add.
  5. In a chat, click + → Connectors and switch the new connector on.

Custom connectors are available on Free, Pro, Max, Team and Enterprise plans (Free is limited to one). On Team and Enterprise an organization Owner adds the connector first under Organization settings → Connectors.

Authorization

After you click Add, a sign-in window for the service opens. Sign in with your own account and approve access. Claude never sees your password.

How to connect True Solar Time to ChatGPT

The server address to paste into ChatGPT settings:

https://true-solar-time--shan-liu-s3.run.tools

  1. Open ChatGPT in a browser (chatgpt.com). A Plus, Pro, Business, Enterprise or Edu plan is required.
  2. Turn on developer mode once: Settings → Apps → Advanced settings → Developer mode.
  3. Open Settings → Connectors and click Create.
  4. Fill in the form: Name (anything), Description (one line about what the service does), MCP server URL (copy it below).
  5. Under Authentication choose OAuth if the service requires sign-in, otherwise None. Click Create.
  6. In a new chat open + → Apps/Connectors and enable the connector.

OpenAI has renamed this section before (Connectors → Apps/Plugins). If the label differs, search settings for "developer mode". On Business/Enterprise workspaces an admin must allow custom connectors first.

Authorization

On first use ChatGPT opens the service's sign-in window. Sign in and approve access.

How to connect True Solar Time to Cursor

The server address to paste into Cursor settings:

https://true-solar-time--shan-liu-s3.run.tools

Fastest: click Open in Cursor below and confirm the prompt.

Manually:

  1. In Cursor open Settings → Cursor Settings → MCP and click Add new global MCP server.
  2. Paste the JSON copied below into ~/.cursor/mcp.json (per project: .cursor/mcp.json in the repo root).
  3. Save the file. The server appears in the MCP list; authorize it there if asked.

Authorization

If the service needs sign-in, an authorize button appears next to the server in the MCP list.

Server tool list (3)

Raw names from tools/list. Only developers need these.

true_solar_timeConvert a recorded birth time (wall clock + IANA time zone + longitude) into true solar time — the time a BaZi / Four Pillars chart should actually be cast from. Returns the corrected instant, the total correction decomposed into DST + longitude + equation-of-time (the three always sum exactly), the resulting two-hour branch, distance to the nearest branch boundary, and whether the reported clock time even existed (spring-forward DST gaps, e.g. China 1986–91). Deterministic.
hour_branchWhich two-hour branch (子丑寅卯…) a given time falls in, and minutes to the nearest branch boundary. Use on an already-corrected time; for raw birth records use true_solar_time.
cast_pillarsCast a BaZi / Four Pillars chart the right way round: true solar time correction FIRST, then the four pillars with hidden stems and Na Yin, plus luck cycles. Runs on the production Auspice Oracle engine — same conventions as auspiceoracle.com/en/method (late Zi keeps the civil day; year/month turn at exact solar-term instants). Facts only: no strength verdicts, no favorable elements, no interpretation. Deterministic.