Date Class
Definition
Important
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The class Date
represents a specific instant
in time, with millisecond precision.
[Android.Runtime.Register("java/util/Date", DoNotGenerateAcw=true)]
public class Date : Java.Lang.Object, IDisposable, Java.Interop.IJavaPeerable, Java.IO.ISerializable, Java.Lang.ICloneable, Java.Lang.IComparable
[<Android.Runtime.Register("java/util/Date", DoNotGenerateAcw=true)>]
type Date = class
inherit Object
interface ISerializable
interface IJavaObject
interface IDisposable
interface IJavaPeerable
interface ICloneable
interface IComparable
- Inheritance
- Derived
- Attributes
- Implements
Remarks
The class Date
represents a specific instant in time, with millisecond precision.
Prior to JDK 1.1, the class Date
had two additional functions. It allowed the interpretation of dates as year, month, day, hour, minute, and second values. It also allowed the formatting and parsing of date strings. Unfortunately, the API for these functions was not amenable to internationalization. As of JDK 1.1, the Calendar
class should be used to convert between dates and time fields and the DateFormat
class should be used to format and parse date strings. The corresponding methods in Date
are deprecated.
Although the Date
class is intended to reflect coordinated universal time (UTC), it may not do so exactly, depending on the host environment of the Java Virtual Machine. Nearly all modern operating systems assume that 1 day = 24 × 60 × 60 = 86400 seconds in all cases. In UTC, however, about once every year or two there is an extra second, called a "leap second." The leap second is always added as the last second of the day, and always on December 31 or June 30. For example, the last minute of the year 1995 was 61 seconds long, thanks to an added leap second. Most computer clocks are not accurate enough to be able to reflect the leap-second distinction.
Some computer standards are defined in terms of Greenwich mean time (GMT), which is equivalent to universal time (UT). GMT is the "civil" name for the standard; UT is the "scientific" name for the same standard. The distinction between UTC and UT is that UTC is based on an atomic clock and UT is based on astronomical observations, which for all practical purposes is an invisibly fine hair to split. Because the earth's rotation is not uniform (it slows down and speeds up in complicated ways), UT does not always flow uniformly. Leap seconds are introduced as needed into UTC so as to keep UTC within 0.9 seconds of UT1, which is a version of UT with certain corrections applied. There are other time and date systems as well; for example, the time scale used by the satellite-based global positioning system (GPS) is synchronized to UTC but is not adjusted for leap seconds. An interesting source of further information is the United States Naval Observatory (USNO): <blockquote>
<a href="http://www.usno.navy.mil/USNO">http://www.usno.navy.mil/USNO</a>
</blockquote>
and the material regarding "Systems of Time" at: <blockquote>
<a href="http://www.usno.navy.mil/USNO/time/master-clock/systems-of-time">http://www.usno.navy.mil/USNO/time/master-clock/systems-of-time</a>
</blockquote>
which has descriptions of various different time systems including UT, UT1, and UTC.
In all methods of class Date
that accept or return year, month, date, hours, minutes, and seconds values, the following representations are used: <ul> <li>A year y is represented by the integer y - 1900
. <li>A month is represented by an integer from 0 to 11; 0 is January, 1 is February, and so forth; thus 11 is December. <li>A date (day of month) is represented by an integer from 1 to 31 in the usual manner. <li>An hour is represented by an integer from 0 to 23. Thus, the hour from midnight to 1 a.m. is hour 0, and the hour from noon to 1 p.m. is hour 12. <li>A minute is represented by an integer from 0 to 59 in the usual manner. <li>A second is represented by an integer from 0 to 61; the values 60 and 61 occur only for leap seconds and even then only in Java implementations that actually track leap seconds correctly. Because of the manner in which leap seconds are currently introduced, it is extremely unlikely that two leap seconds will occur in the same minute, but this specification follows the date and time conventions for ISO C. </ul>
In all cases, arguments given to methods for these purposes need not fall within the indicated ranges; for example, a date may be specified as January 32 and is interpreted as meaning February 1.
Added in 1.0.
Java documentation for java.util.Date
.
Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.
Constructors
Date() |
Allocates a |
Date(Int32, Int32, Int32, Int32, Int32, Int32) |
Obsolete.
Allocates a |
Date(Int32, Int32, Int32, Int32, Int32) |
Obsolete.
Allocates a |
Date(Int32, Int32, Int32) |
Obsolete.
Allocates a |
Date(Int64) |
Allocates a |
Date(IntPtr, JniHandleOwnership) |
A constructor used when creating managed representations of JNI objects; called by the runtime. |
Date(String) |
Obsolete.
Allocates a |
Properties
Class |
Returns the runtime class of this |
Day |
Obsolete.
Returns the day of the week represented by this date. |
Handle |
The handle to the underlying Android instance. (Inherited from Object) |
Hours |
Obsolete.
Returns the hour represented by this |
JniIdentityHashCode | (Inherited from Object) |
JniPeerMembers | |
Minutes |
Obsolete.
Returns the number of minutes past the hour represented by this date,
as interpreted in the local time zone. -or- Sets the minutes of this |
Month |
Obsolete.
Returns a number representing the month that contains or begins
with the instant in time represented by this |
PeerReference | (Inherited from Object) |
Seconds |
Obsolete.
Returns the number of seconds past the minute represented by this date. -or- Sets the seconds of this |
ThresholdClass |
This API supports the Mono for Android infrastructure and is not intended to be used directly from your code. |
ThresholdType |
This API supports the Mono for Android infrastructure and is not intended to be used directly from your code. |
Time |
Returns the number of milliseconds since January 1, 1970, 00:00:00 GMT
represented by this |
TimezoneOffset |
Obsolete.
Returns the offset, measured in minutes, for the local time zone
relative to UTC that is appropriate for the time represented by
this |
Year |
Obsolete.
Returns a value that is the result of subtracting 1900 from the
year that contains or begins with the instant in time represented
by this |
Methods
After(Date) |
Tests if this date is after the specified date. |
Before(Date) |
Tests if this date is before the specified date. |
Clone() |
Return a copy of this object. |
CompareTo(Date) |
Compares two Dates for ordering. |
Dispose() | (Inherited from Object) |
Dispose(Boolean) | (Inherited from Object) |
Equals(Object) |
Indicates whether some other object is "equal to" this one. (Inherited from Object) |
From(Instant) |
Obtains an instance of |
GetDate() |
Obsolete.
Returns the day of the month represented by this |
GetHashCode() |
Returns a hash code value for the object. (Inherited from Object) |
JavaFinalize() |
Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. (Inherited from Object) |
Notify() |
Wakes up a single thread that is waiting on this object's monitor. (Inherited from Object) |
NotifyAll() |
Wakes up all threads that are waiting on this object's monitor. (Inherited from Object) |
Parse(String) |
Obsolete.
Attempts to interpret the string |
SetDate(Int32) |
Obsolete.
Sets the day of the month of this |
SetHandle(IntPtr, JniHandleOwnership) |
Sets the Handle property. (Inherited from Object) |
ToArray<T>() | (Inherited from Object) |
ToGMTString() |
Obsolete.
Creates a string representation of this |
ToInstant() |
Converts this |
ToLocaleString() |
Obsolete.
Creates a string representation of this |
ToString() |
Returns a string representation of the object. (Inherited from Object) |
UnregisterFromRuntime() | (Inherited from Object) |
UTC(Int32, Int32, Int32, Int32, Int32, Int32) |
Obsolete.
Determines the date and time based on the arguments. |
Wait() |
Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>. (Inherited from Object) |
Wait(Int64, Int32) |
Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>, or until a certain amount of real time has elapsed. (Inherited from Object) |
Wait(Int64) |
Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>, or until a certain amount of real time has elapsed. (Inherited from Object) |
Explicit Interface Implementations
IComparable.CompareTo(Object) | |
IJavaPeerable.Disposed() | (Inherited from Object) |
IJavaPeerable.DisposeUnlessReferenced() | (Inherited from Object) |
IJavaPeerable.Finalized() | (Inherited from Object) |
IJavaPeerable.JniManagedPeerState | (Inherited from Object) |
IJavaPeerable.SetJniIdentityHashCode(Int32) | (Inherited from Object) |
IJavaPeerable.SetJniManagedPeerState(JniManagedPeerStates) | (Inherited from Object) |
IJavaPeerable.SetPeerReference(JniObjectReference) | (Inherited from Object) |
Extension Methods
JavaCast<TResult>(IJavaObject) |
Performs an Android runtime-checked type conversion. |
JavaCast<TResult>(IJavaObject) | |
GetJniTypeName(IJavaPeerable) |