Time¶

Source: AI/Tools/TimeTools.cs

Conversions between time scales and between calendar/Julian/MJD/ephemeris-time representations. See Standards & Units → Time for ISO 8601 formatting rules.

ConvertDateTime¶

Convert a date/time to another time scale, preserving the instant.

Parameter	Type	Description
`dateTime`	`Time`	The instant to convert
`kindTarget`	`DateKind`	`UTC`, `TDB`, `TAI`, `TDT`, `GPS`, or `Local`

{
  "dateTime": { "dateTime": "2024-01-01T00:00:00", "kind": "UTC" },
  "kindTarget": "TDB"
}

CurrentDateTime¶

Return the current UTC instant. No parameters.

ConvertToJulianDate¶

Convert an instant to its Julian Date (days) in the same time scale.

Parameter	Type
`dateTime`	`Time`

ConvertFromJulianDate¶

Build an instant from a Julian Date.

Parameter	Type
`julianDate`	days (double)
`kind`	`DateKind`

ConvertToModifiedJulianDate¶

MJD = JD − 2400000.5. Same input as ConvertToJulianDate.

ConvertToEphemerisTime¶

Convert an instant to ephemeris time — TDB seconds elapsed since J2000 (2000-01-01T12:00:00 TDB).

Parameter	Type
`dateTime`	`Time`

ConvertFromEphemerisTime¶

Inverse of ConvertToEphemerisTime. Returns a TDB Time.

Parameter	Type
`ephemerisTime`	seconds (double)

AddDuration¶

Add a signed duration in seconds to an instant, preserving its time scale.

Parameter	Type
`dateTime`	`Time`
`seconds`	double (may be negative)