Time

EPOCH_JULIAN_DAY

int EPOCH_JULIAN_DAY

The Julian day of the epoch, that is, January 1, 1970 on the Gregorian calendar.

Constant Value: 2440588 (0x00253d8c)

FRIDAY

int FRIDAY

Constant Value: 5 (0x00000005)

HOUR

int HOUR

Constant Value: 3 (0x00000003)

MINUTE

int MINUTE

Constant Value: 2 (0x00000002)

MONDAY

int MONDAY

Constant Value: 1 (0x00000001)

MONDAY_BEFORE_JULIAN_EPOCH

int MONDAY_BEFORE_JULIAN_EPOCH

The Julian day of the Monday in the week of the epoch, December 29, 1969 on the Gregorian calendar.

Constant Value: 2440585 (0x00253d89)

MONTH

int MONTH

Constant Value: 5 (0x00000005)

MONTH_DAY

int MONTH_DAY

Constant Value: 4 (0x00000004)

SATURDAY

int SATURDAY

Constant Value: 6 (0x00000006)

SECOND

int SECOND

Constant Value: 1 (0x00000001)

SUNDAY

int SUNDAY

Constant Value: 0 (0x00000000)

THURSDAY

int THURSDAY

Constant Value: 4 (0x00000004)

TIMEZONE_UTC

String TIMEZONE_UTC

Constant Value: "UTC"

TUESDAY

int TUESDAY

Constant Value: 2 (0x00000002)

WEDNESDAY

int WEDNESDAY

Constant Value: 3 (0x00000003)

WEEK_DAY

int WEEK_DAY

Constant Value: 7 (0x00000007)

WEEK_NUM

int WEEK_NUM

Constant Value: 9 (0x00000009)

YEAR

int YEAR

Constant Value: 6 (0x00000006)

YEAR_DAY

int YEAR_DAY

Constant Value: 8 (0x00000008)

allDay

boolean allDay

True if this is an allDay event. The hour, minute, second fields are all zero, and the date is displayed the same in all time zones.

gmtoff

long gmtoff

Offset in seconds from UTC including any DST offset.

hour

int hour

Hour of day [0-23]

isDst

int isDst

This time is in daylight savings time. One of:

• positive - in dst
• 0 - not in dst
• negative - unknown

minute

int minute

Minute [0-59]

month

int month

Month [0-11]

monthDay

int monthDay

Day of month [1-31]

second

int second

Seconds [0-61] (2 leap seconds allowed)

timezone

String timezone

The timezone for this Time. Should not be null.

weekDay

int weekDay

Day of week [0-6]

year

int year

Year. For example, 1970.

yearDay

int yearDay

Day of year [0-365]

Time

Time (String timezoneId)

Construct a Time object in the timezone named by the string argument "timezone". The time is initialized to Jan 1, 1970.

Parameters
timezoneId	String: string containing the timezone to use.

Time

Time ()

Construct a Time object in the default timezone. The time is initialized to Jan 1, 1970.

Time

Time (Time other)

A copy constructor. Construct a Time object by copying the given Time object. No normalization occurs.

after

boolean after (Time that)

Returns true if the time represented by this Time object occurs after the given time.

Equivalent to Time.compare(this, that) > 0. See compare(Time, Time) for details.

Parameters
that	Time: a given Time object to compare against

Returns
boolean	true if this time is greater than the given time

before

boolean before (Time that)

Returns true if the time represented by this Time object occurs before the given time.

Equivalent to Time.compare(this, that) < 0. See compare(Time, Time) for details.

Parameters
that	Time: a given Time object to compare against

Returns
boolean	true if this time is less than the given time

clear

void clear (String timezoneId)

Clears all values, setting the timezone to the given timezone. Sets isDst to a negative value to mean "unknown".

Parameters
timezoneId	String: the timezone to use.

compare

int compare (Time a, 
                Time b)

Compare two Time objects and return a negative number if a is less than b, a positive number if a is greater than b, or 0 if they are equal.

This method can return an incorrect answer when the date / time fields of either Time have been set to a local time that contradicts the available timezone information.

Parameters
a	Time: first Time instance to compare
b	Time: second Time instance to compare

Returns
int	a negative result if a is earlier, a positive result if b is earlier, or 0 if they are equal.

Throws
NullPointerException	if either argument is null
IllegalArgumentException	if allDay is true but hour, minute, and second are not 0.

format

String format (String format)

Print the current value given the format string provided. See man strftime for what means what. The final string must be less than 256 characters.

Parameters
format	String: a string containing the desired format.

Returns
String	a String containing the current time expressed in the current locale.

format2445

String format2445 ()

Format according to RFC 2445 DATE-TIME type.

The same as format("%Y%m%dT%H%M%S"), or format("%Y%m%dT%H%M%SZ") for a Time with a timezone set to "UTC".

Returns
String

format3339

String format3339 (boolean allDay)

Return a string in the RFC 3339 format.

If allDay is true, expresses the time as Y-M-D

Otherwise, if the timezone is UTC, expresses the time as Y-M-D-T-H-M-S UTC

Otherwise the time is expressed the time as Y-M-D-T-H-M-S +- GMT

Parameters
allDay	boolean

Returns
String	string in the RFC 3339 format.

getActualMaximum

int getActualMaximum (int field)

Return the maximum possible value for the given field given the value of the other fields. Requires that it be normalized for MONTH_DAY and YEAR_DAY.

Parameters
field	int: one of the constants for HOUR, MINUTE, SECOND, etc.

Returns
int	the maximum value for the field.

getCurrentTimezone

String getCurrentTimezone ()

Returns the timezone string that is currently set for the device.

Returns
String

getJulianDay

int getJulianDay (long millis, 
                long gmtoff)

Computes the Julian day number for a point in time in a particular timezone. The Julian day for a given date is the same for every timezone. For example, the Julian day for July 1, 2008 is 2454649.

Callers must pass the time in UTC millisecond (as can be returned by toMillis(boolean) or normalize(boolean)) and the offset from UTC of the timezone in seconds (as might be in gmtoff).

The Julian day is useful for testing if two events occur on the same calendar date and for determining the relative time of an event from the present ("yesterday", "3 days ago", etc.).

Parameters
millis	long: the time in UTC milliseconds
gmtoff	long: the offset from UTC in seconds

Returns
int	the Julian day

getJulianMondayFromWeeksSinceEpoch

int getJulianMondayFromWeeksSinceEpoch (int week)

Takes a number of weeks since the epoch and calculates the Julian day of the Monday for that week. This assumes that the week containing the EPOCH_JULIAN_DAY is considered week 0. It returns the Julian day for the Monday week weeks after the Monday of the week containing the epoch.

Parameters
week	int: Number of weeks since the epoch

Returns
int	The julian day for the Monday of the given week since the epoch

getWeekNumber

int getWeekNumber ()

Computes the week number according to ISO 8601. The current Time object must already be normalized because this method uses the yearDay and weekDay fields.

In IS0 8601, weeks start on Monday. The first week of the year (week 1) is defined by ISO 8601 as the first week with four or more of its days in the starting year. Or equivalently, the week containing January 4. Or equivalently, the week with the year's first Thursday in it.

The week number can be calculated by counting Thursdays. Week N contains the Nth Thursday of the year.

Returns
int	the ISO week number.

getWeeksSinceEpochFromJulianDay

int getWeeksSinceEpochFromJulianDay (int julianDay, 
                int firstDayOfWeek)

Returns the week since EPOCH_JULIAN_DAY (Jan 1, 1970) adjusted for first day of week. This takes a julian day and the week start day and calculates which week since EPOCH_JULIAN_DAY that day occurs in, starting at 0. *Do not* use this to compute the ISO week number for the year.

Parameters
julianDay	int: The julian day to calculate the week number for
firstDayOfWeek	int: Which week day is the first day of the week, see SUNDAY

Returns
int	Weeks since the epoch

isEpoch

boolean isEpoch (Time time)

Returns true if the day of the given time is the epoch on the Julian Calendar (January 1, 1970 on the Gregorian calendar).

This method can return an incorrect answer when the date / time fields have been set to a local time that contradicts the available timezone information.

Parameters
time	Time: the time to test

Returns
boolean	true if epoch.

normalize

long normalize (boolean ignoreDst)

Ensures the values in each field are in range. For example if the current value of this calendar is March 32, normalize() will convert it to April 1. It also fills in weekDay, yearDay, isDst and gmtoff.

If "ignoreDst" is true, then this method sets the "isDst" field to -1 (the "unknown" value) before normalizing. It then computes the time in milliseconds and sets the correct value for "isDst" if the fields resolve to a valid date / time.

See toMillis(boolean) for more information about when to use true or false for "ignoreDst" and when -1 might be returned.

Parameters
ignoreDst	boolean

Returns
long	the UTC milliseconds since the epoch, or -1

parse

boolean parse (String s)

Parses a date-time string in either the RFC 2445 format or an abbreviated format that does not include the "time" field. For example, all of the following strings are valid:

• "20081013T160000Z"
• "20081013T160000"
• "20081013"

Returns whether or not the time is in UTC (ends with Z). If the string ends with "Z" then the timezone is set to UTC. If the date-time string included only a date and no time field, then the allDay field of this Time class is set to true and the hour, minute, and second fields are set to zero; otherwise (a time field was included in the date-time string) allDay is set to false. The fields weekDay, yearDay, and gmtoff are always set to zero, and the field isDst is set to -1 (unknown). To set those fields, call normalize(boolean) after parsing. To parse a date-time string and convert it to UTC milliseconds, do something like this:

   Time time = new Time();
   String date = "20081013T160000Z";
   time.parse(date);
   long millis = time.normalize(false);
 

Parameters
s	String: the string to parse

Returns
boolean	true if the resulting time value is in UTC time

Throws
TimeFormatException	if s cannot be parsed.

parse3339

boolean parse3339 (String s)

Parse a time in RFC 3339 format. This method also parses simple dates (that is, strings that contain no time or time offset). For example, all of the following strings are valid:

• "2008-10-13T16:00:00.000Z"
• "2008-10-13T16:00:00.000+07:00"
• "2008-10-13T16:00:00.000-07:00"
• "2008-10-13"

If the string contains a time and time offset, then the time offset will be used to convert the time value to UTC.

If the given string contains just a date (with no time field), then the allDay field is set to true and the hour, minute, and second fields are set to zero.

Returns true if the resulting time value is in UTC time.

Parameters
s	String: the string to parse

Returns
boolean	true if the resulting time value is in UTC time

Throws
TimeFormatException	if s cannot be parsed.

set

void set (Time that)

Copy the value of that to this Time object. No normalization happens.

Parameters
that	Time

set

void set (int second, 
                int minute, 
                int hour, 
                int monthDay, 
                int month, 
                int year)

Sets the fields. Sets weekDay, yearDay and gmtoff to 0, and isDst to -1. Call normalize(boolean) if you need those.

Parameters
second	int
minute	int
hour	int
monthDay	int
month	int
year	int

set

void set (int monthDay, 
                int month, 
                int year)

Sets the date from the given fields. Also sets allDay to true. Sets weekDay, yearDay and gmtoff to 0, and isDst to -1. Call normalize(boolean) if you need those.

Parameters
monthDay	int: the day of the month (in the range [1,31])
month	int: the zero-based month number (in the range [0,11])
year	int: the year

set

void set (long millis)

Sets the fields in this Time object given the UTC milliseconds. After this method returns, all the fields are normalized. This also sets the "isDst" field to the correct value.

Parameters
millis	long: the time in UTC milliseconds since the epoch.

setJulianDay

long setJulianDay (int julianDay)

Sets the time from the given Julian day number, which must be based on the same timezone that is set in this Time object. The "gmtoff" field need not be initialized because the given Julian day may have a different GMT offset than whatever is currently stored in this Time object anyway. After this method returns all the fields will be normalized and the time will be set to 12am at the beginning of the given Julian day.

The only exception to this is if 12am does not exist for that day because of daylight saving time. For example, Cairo, Eqypt moves time ahead one hour at 12am on April 25, 2008 and there are a few other places that also change daylight saving time at 12am. In those cases, the time will be set to 1am.

Parameters
julianDay	int: the Julian day in the timezone for this Time object

Returns
long	the UTC milliseconds for the beginning of the Julian day

setToNow

void setToNow ()

Sets the time of the given Time object to the current time.

switchTimezone

void switchTimezone (String timezone)

Convert this time object so the time represented remains the same, but is instead located in a different timezone. This method automatically calls normalize() in some cases.

This method can return incorrect results if the date / time cannot be normalized.

Parameters
timezone	String

toMillis

long toMillis (boolean ignoreDst)

Converts this time to milliseconds. Suitable for interacting with the standard java libraries. The time is in UTC milliseconds since the epoch. This does an implicit normalization to compute the milliseconds but does not change any of the fields in this Time object. If you want to normalize the fields in this Time object and also get the milliseconds then use normalize(boolean).

If "ignoreDst" is false, then this method uses the current setting of the "isDst" field and will adjust the returned time if the "isDst" field is wrong for the given time. See the sample code below for an example of this.

If "ignoreDst" is true, then this method ignores the current setting of the "isDst" field in this Time object and will instead figure out the correct value of "isDst" (as best it can) from the fields in this Time object. The only case where this method cannot figure out the correct value of the "isDst" field is when the time is inherently ambiguous because it falls in the hour that is repeated when switching from Daylight-Saving Time to Standard Time.

Here is an example where toMillis(true) adjusts the time, assuming that DST changes at 2am on Sunday, Nov 4, 2007.

 Time time = new Time();
 time.set(4, 10, 2007);  // set the date to Nov 4, 2007, 12am
 time.normalize(false);       // this sets isDst = 1
 time.monthDay += 1;     // changes the date to Nov 5, 2007, 12am
 millis = time.toMillis(false);   // millis is Nov 4, 2007, 11pm
 millis = time.toMillis(true);    // millis is Nov 5, 2007, 12am
 

To avoid this problem, use toMillis(true) after adding or subtracting days or explicitly setting the "monthDay" field. On the other hand, if you are adding or subtracting hours or minutes, then you should use toMillis(false).

You should also use toMillis(false) if you want to read back the same milliseconds that you set with set(long)

This method can return -1 when the date / time fields have been set to a local time that conflicts with available timezone information. For example, when daylight savings transitions cause an hour to be skipped: times within that hour will return -1 if isDst = -1. or set(Time) or after parsing a date string.

Parameters
ignoreDst	boolean

Returns
long

toString

String toString ()

Return the current time in YYYYMMDDTHHMMSS format

Returns
String	a string representation of the object.