Retrograde Periods

GET/api/retrogradesPro

Get retrograde station dates for planets computed via binary search at minute precision. Returns when each planet stations retrograde and direct, with HD gate positions.

Legacy URL supported

The previous endpoint path /api/retrograde-periods is still supported and will continue to work.

Request

Parameters

startDate reqstringStart date in YYYY-MM-DD format

endDate reqstringEnd date in YYYY-MM-DD format (max 730 days / 2 years)

planets stringComma-separated planet names to filter (e.g. "Mercury,Venus,Mars"). Defaults to all retrograde-capable planets.

Available planets

Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto, NorthNode.

Sun, Moon, Earth, and SouthNode do not retrograde.

thd-api

Response

✓ doneapplication/json

{
"success": true,
"meta": {
  "endpoint": "retrograde-periods",
  "startDate": "2026-01-01",
  "endDate": "2026-12-31",
  "periodCount": 4,
  "granularity": "minute",
  "availablePlanets": ["Mercury", "Venus", "Mars", "Jupiter", "Saturn", "Uranus", "Neptune", "Pluto", "NorthNode"]
},
"data": [
  {
    "planet": "Mercury",
    "retrograde_start": "2026-03-15T08:42:00.000Z",
    "retrograde_end": "2026-04-07T14:18:00.000Z",
    "duration_days": 23.23,
    "start_gate": 17,
    "start_line": 3,
    "end_gate": 51,
    "end_line": 6,
    "is_open": false,
    "retrograde_entire_range": false
  },
  {
    "planet": "Mercury",
    "retrograde_start": "2026-07-10T22:15:00.000Z",
    "retrograde_end": "2026-08-04T11:33:00.000Z",
    "duration_days": 24.55,
    "start_gate": 56,
    "start_line": 1,
    "end_gate": 31,
    "end_line": 4,
    "is_open": false,
    "retrograde_entire_range": false
  }
]
}

Field	Description
`planet`	Planet name
`retrograde_start`	ISO timestamp when planet stations retrograde, or `null` if already retrograde at range start
`retrograde_end`	ISO timestamp when planet stations direct, or `null` if still retrograde at range end
`duration_days`	Duration of retrograde period in days
`start_gate` / `start_line`	HD gate and line at retrograde station
`end_gate` / `end_line`	HD gate and line at direct station, or `null` if still retrograde
`is_open`	`true` if retrograde period extends beyond the requested date range
`retrograde_entire_range`	`true` if the planet is retrograde for the entire requested range

Chart requests

1 chart request per call (flat rate). Maximum range: 730 days (2 years).