new JulianDate(julianDayNumberopt, secondsOfDayopt, timeStandardopt)
Represents an astronomical Julian date, which is the number of days since noon on January 1, -4712 (4713 BC).
For increased precision, this class stores the whole number part of the date and the seconds
part of the date in separate components. In order to be safe for arithmetic and represent
leap seconds, the date is always stored in the International Atomic Time standard
TimeStandard.TAI.
Parameters:
| Name | Type | Attributes | Default | Description |
|---|---|---|---|---|
julianDayNumber |
Number |
<optional> |
0.0 | The Julian Day Number representing the number of whole days. Fractional days will also be handled correctly. |
secondsOfDay |
Number |
<optional> |
0.0 | The number of seconds into the current Julian Day Number. Fractional seconds, negative seconds and seconds greater than a day will be handled correctly. |
timeStandard |
TimeStandard |
<optional> |
TimeStandard.UTC | The time standard in which the first two parameters are defined. |
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Members
(static) leapSeconds :Array.<LeapSecond>
Gets or sets the list of leap seconds used throughout Cesium.
Type:
- Array.<LeapSecond>
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dayNumber :Number
Gets or sets the number of whole days.
Type:
- Number
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secondsOfDay :Number
Gets or sets the number of seconds into the current day.
Type:
- Number
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Methods
(static) addDays(julianDate, days, result) → {JulianDate}
Adds the provided number of days to the provided date instance.
Parameters:
| Name | Type | Description |
|---|---|---|
julianDate |
JulianDate | The date. |
days |
Number | The number of days to add or subtract. |
result |
JulianDate | An existing instance to use for the result. |
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Returns:
The modified result parameter.
- Type
- JulianDate
(static) addHours(julianDate, hours, result) → {JulianDate}
Adds the provided number of hours to the provided date instance.
Parameters:
| Name | Type | Description |
|---|---|---|
julianDate |
JulianDate | The date. |
hours |
Number | The number of hours to add or subtract. |
result |
JulianDate | An existing instance to use for the result. |
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Returns:
The modified result parameter.
- Type
- JulianDate
(static) addMinutes(julianDate, minutes, result) → {JulianDate}
Adds the provided number of minutes to the provided date instance.
Parameters:
| Name | Type | Description |
|---|---|---|
julianDate |
JulianDate | The date. |
minutes |
Number | The number of minutes to add or subtract. |
result |
JulianDate | An existing instance to use for the result. |
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Returns:
The modified result parameter.
- Type
- JulianDate
(static) addSeconds(julianDate, seconds, result) → {JulianDate}
Adds the provided number of seconds to the provided date instance.
Parameters:
| Name | Type | Description |
|---|---|---|
julianDate |
JulianDate | The date. |
seconds |
Number | The number of seconds to add or subtract. |
result |
JulianDate | An existing instance to use for the result. |
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Returns:
The modified result parameter.
- Type
- JulianDate
(static) clone(julianDate, resultopt) → {JulianDate}
Duplicates a JulianDate instance.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
julianDate |
JulianDate | The date to duplicate. | |
result |
JulianDate |
<optional> |
An existing instance to use for the result. |
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Returns:
The modified result parameter or a new instance if none was provided. Returns undefined if julianDate is undefined.
- Type
- JulianDate
(static) compare(left, right) → {Number}
Compares two instances.
Parameters:
| Name | Type | Description |
|---|---|---|
left |
JulianDate | The first instance. |
right |
JulianDate | The second instance. |
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Returns:
A negative value if left is less than right, a positive value if left is greater than right, or zero if left and right are equal.
- Type
- Number
(static) computeTaiMinusUtc(julianDate) → {Number}
Computes the number of seconds the provided instance is ahead of UTC.
Parameters:
| Name | Type | Description |
|---|---|---|
julianDate |
JulianDate | The date. |
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Returns:
The number of seconds the provided instance is ahead of UTC
- Type
- Number
(static) daysDifference(left, right) → {Number}
Computes the difference in days between the provided instance.
Parameters:
| Name | Type | Description |
|---|---|---|
left |
JulianDate | The first instance. |
right |
JulianDate | The second instance. |
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Returns:
The difference, in days, when subtracting
right from left.
- Type
- Number
(static) equals(leftopt, rightopt) → {Boolean}
Compares two instances and returns
true if they are equal, false otherwise.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
left |
JulianDate |
<optional> |
The first instance. |
right |
JulianDate |
<optional> |
The second instance. |
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Returns:
true if the dates are equal; otherwise, false.
- Type
- Boolean
(static) equalsEpsilon(leftopt, rightopt, epsilon) → {Boolean}
Compares two instances and returns
true if they are within epsilon seconds of
each other. That is, in order for the dates to be considered equal (and for
this function to return true), the absolute value of the difference between them, in
seconds, must be less than epsilon.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
left |
JulianDate |
<optional> |
The first instance. |
right |
JulianDate |
<optional> |
The second instance. |
epsilon |
Number | The maximum number of seconds that should separate the two instances. |
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Returns:
true if the two dates are within epsilon seconds of each other; otherwise false.
- Type
- Boolean
(static) fromDate(date, resultopt) → {JulianDate}
Creates a new instance from a JavaScript Date.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
date |
Date | A JavaScript Date. | |
result |
JulianDate |
<optional> |
An existing instance to use for the result. |
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Throws:
-
date must be a valid JavaScript Date.
- Type
- DeveloperError
Returns:
The modified result parameter or a new instance if none was provided.
- Type
- JulianDate
(static) fromIso8601(iso8601String, resultopt) → {JulianDate}
Creates a new instance from a from an ISO 8601 date.
This method is superior to
Date.parse because it will handle all valid formats defined by the ISO 8601
specification, including leap seconds and sub-millisecond times, which discarded by most JavaScript implementations.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
iso8601String |
String | An ISO 8601 date. | |
result |
JulianDate |
<optional> |
An existing instance to use for the result. |
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Throws:
-
Invalid ISO 8601 date.
- Type
- DeveloperError
Returns:
The modified result parameter or a new instance if none was provided.
- Type
- JulianDate
(static) greaterThan(left, right) → {Boolean}
Compares the provided instances and returns
true if left is later than right, false otherwise.
Parameters:
| Name | Type | Description |
|---|---|---|
left |
JulianDate | The first instance. |
right |
JulianDate | The second instance. |
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Returns:
true if left is later than right, false otherwise.
- Type
- Boolean
(static) greaterThanOrEquals(left, right) → {Boolean}
Compares the provided instances and returns
true if left is later than or equal to right, false otherwise.
Parameters:
| Name | Type | Description |
|---|---|---|
left |
JulianDate | The first instance. |
right |
JulianDate | The second instance. |
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Returns:
true if left is later than or equal to right, false otherwise.
- Type
- Boolean
(static) lessThan(left, right) → {Boolean}
Compares the provided instances and returns
true if left is earlier than right, false otherwise.
Parameters:
| Name | Type | Description |
|---|---|---|
left |
JulianDate | The first instance. |
right |
JulianDate | The second instance. |
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Returns:
true if left is earlier than right, false otherwise.
- Type
- Boolean
(static) lessThanOrEquals(left, right) → {Boolean}
Compares the provided instances and returns
true if left is earlier than or equal to right, false otherwise.
Parameters:
| Name | Type | Description |
|---|---|---|
left |
JulianDate | The first instance. |
right |
JulianDate | The second instance. |
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Returns:
true if left is earlier than or equal to right, false otherwise.
- Type
- Boolean
(static) now(resultopt) → {JulianDate}
Creates a new instance that represents the current system time.
This is equivalent to calling
JulianDate.fromDate(new Date());.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
result |
JulianDate |
<optional> |
An existing instance to use for the result. |
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Returns:
The modified result parameter or a new instance if none was provided.
- Type
- JulianDate
(static) secondsDifference(left, right) → {Number}
Computes the difference in seconds between the provided instance.
Parameters:
| Name | Type | Description |
|---|---|---|
left |
JulianDate | The first instance. |
right |
JulianDate | The second instance. |
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Returns:
The difference, in seconds, when subtracting
right from left.
- Type
- Number
(static) toDate(julianDate) → {Date}
Creates a JavaScript Date from the provided instance.
Since JavaScript dates are only accurate to the nearest millisecond and
cannot represent a leap second, consider using
JulianDate.toGregorianDate instead.
If the provided JulianDate is during a leap second, the previous second is used.
Parameters:
| Name | Type | Description |
|---|---|---|
julianDate |
JulianDate | The date to be converted. |
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Returns:
A new instance representing the provided date.
- Type
- Date
(static) toGregorianDate(julianDate, resultopt) → {GregorianDate}
Creates a
GregorianDate from the provided instance.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
julianDate |
JulianDate | The date to be converted. | |
result |
GregorianDate |
<optional> |
An existing instance to use for the result. |
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Returns:
The modified result parameter or a new instance if none was provided.
- Type
- GregorianDate
(static) toIso8601(julianDate, precisionopt) → {String}
Creates an ISO8601 representation of the provided date.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
julianDate |
JulianDate | The date to be converted. | |
precision |
Number |
<optional> |
The number of fractional digits used to represent the seconds component. By default, the most precise representation is used. |
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Returns:
The ISO8601 representation of the provided date.
- Type
- String
(static) totalDays(julianDate) → {Number}
Computes the total number of whole and fractional days represented by the provided instance.
Parameters:
| Name | Type | Description |
|---|---|---|
julianDate |
JulianDate | The date. |
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Returns:
The Julian date as single floating point number.
- Type
- Number
clone(resultopt) → {JulianDate}
Duplicates this instance.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
result |
JulianDate |
<optional> |
An existing instance to use for the result. |
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Returns:
The modified result parameter or a new instance if none was provided.
- Type
- JulianDate
equals(rightopt) → {Boolean}
Compares this and the provided instance and returns
true if they are equal, false otherwise.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
right |
JulianDate |
<optional> |
The second instance. |
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Returns:
true if the dates are equal; otherwise, false.
- Type
- Boolean
equalsEpsilon(rightopt, epsilon) → {Boolean}
Compares this and the provided instance and returns
true if they are within epsilon seconds of
each other. That is, in order for the dates to be considered equal (and for
this function to return true), the absolute value of the difference between them, in
seconds, must be less than epsilon.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
right |
JulianDate |
<optional> |
The second instance. |
epsilon |
Number | The maximum number of seconds that should separate the two instances. |
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Returns:
true if the two dates are within epsilon seconds of each other; otherwise false.
- Type
- Boolean
toString() → {String}
Creates a string representing this date in ISO8601 format.
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Returns:
A string representing this date in ISO8601 format.
- Type
- String