Package org.apache.tools.ant.util

# Class DateUtils

java.lang.Object
org.apache.tools.ant.util.DateUtils

public final class DateUtils extends Object
Helper methods to deal with date/time formatting with a specific defined format (ISO8601) or a correct pluralization of elapsed time in minutes and seconds.

Since:
  Ant 1.5

## Field Summary

Fields
Modifier and Type
Field
Description
`static final DateFormat`
`DATE_HEADER_FORMAT`
Deprecated.
DateFormat is not thread safe, and we cannot guarantee that some other code is using the format in parallel.
`static final ThreadLocal<DateFormat>`
`EN_US_DATE_FORMAT_MIN`
Provides a thread-local US-style date format.
`static final ThreadLocal<DateFormat>`
`EN_US_DATE_FORMAT_SEC`
Provides a thread-local US-style date format.
`static final String`
`ISO8601_DATE_PATTERN`
ISO8601-like pattern for date.
`static final String`
`ISO8601_DATETIME_PATTERN`
ISO8601-like pattern for date-time.
`static final String`
`ISO8601_TIME_PATTERN`
ISO8601-like pattern for time.

## Method Summary

Modifier and Type
Method
Description
`static String`
`format(long date, String pattern)`
Format a date/time into a specific pattern.
`static String`
`format(Date date, String pattern)`
Format a date/time into a specific pattern.
`static String`
`formatElapsedTime(long millis)`
Format an elapsed time into a pluralization correct string.
`static String`
`getDateForHeader()`
Returns the current Date in a format suitable for a SMTP date header.
`static int`
`getPhaseOfMoon(Calendar cal)`
Calculate the phase of the moon for a given date.
`static Date`
`parseDateFromHeader(String datestr)`
Parses the string in a format suitable for a SMTP date header.
`static Date`
`parseIso8601Date(String datestr)`
Parse a string as a date using the ISO8601_DATE format which is `yyyy-MM-dd`
`static Date`
`parseIso8601DateTime(String datestr)`
Parse a string as a datetime using the ISO8601_DATETIME format which is `yyyy-MM-dd'T'HH:mm:ss`
`static Date`
`parseIso8601DateTimeOrDate(String datestr)`
Parse a string as a date using the either the ISO8601_DATETIME or ISO8601_DATE formats.
`static Date`
`parseLenientDateTime(String dateStr)`
Parse a lenient ISO 8601, ms since epoch, or `<touch>`-style date.

### Methods inherited from class java.lang.Object

`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

## Field Details

### ISO8601_DATETIME_PATTERN

public static final String ISO8601_DATETIME_PATTERN
ISO8601-like pattern for date-time. It does not support timezone. `yyyy-MM-ddTHH:mm:ss`

See Also:
  - Constant Field Values

### ISO8601_DATE_PATTERN

public static final String ISO8601_DATE_PATTERN
ISO8601-like pattern for date. `yyyy-MM-dd`

See Also:
  - Constant Field Values

### ISO8601_TIME_PATTERN

public static final String ISO8601_TIME_PATTERN
ISO8601-like pattern for time. `HH:mm:ss`

See Also:
  - Constant Field Values

### DATE_HEADER_FORMAT

@Deprecated public static final DateFormat DATE_HEADER_FORMAT
Deprecated.
DateFormat is not thread safe, and we cannot guarantee that some other code is using the format in parallel. Deprecated since ant 1.8
Format used for SMTP (and probably other) Date headers.

### EN_US_DATE_FORMAT_MIN

public static final ThreadLocal<DateFormat> EN_US_DATE_FORMAT_MIN
Provides a thread-local US-style date format. Exactly as used by `<touch>`, to minute precision: `SimpleDateFormat("MM/dd/yyyy hh:mm a", Locale.US)`

Since:
  Ant 1.10.2

### EN_US_DATE_FORMAT_SEC

public static final ThreadLocal<DateFormat> EN_US_DATE_FORMAT_SEC
Provides a thread-local US-style date format. Exactly as used by `<touch>`, to second precision: `SimpleDateFormat("MM/dd/yyyy hh:mm:ss a", Locale.US)`

Since:
  Ant 1.10.2

## Method Details

### format

public static String format(long date, String pattern)
Format a date/time into a specific pattern.

Parameters:
  `date` - the date to format expressed in milliseconds.
  `pattern` - the pattern to use to format the date.
Returns:
  the formatted date.

### format

public static String format(Date date, String pattern)
Format a date/time into a specific pattern.

Parameters:
  `date` - the date to format expressed in milliseconds.
  `pattern` - the pattern to use to format the date.
Returns:
  the formatted date.

### formatElapsedTime

public static String formatElapsedTime(long millis)
Format an elapsed time into a pluralization correct string. It is limited only to report elapsed time in minutes and seconds and has the following behavior.

- minutes are not displayed when 0. (ie: "45 seconds")
- seconds are always displayed in plural form (ie "0 seconds" or "10 seconds") except for 1 (ie "1 second")

Parameters:
  `millis` - the elapsed time to report in milliseconds.
Returns:
  the formatted text in minutes/seconds.

### getPhaseOfMoon

public static int getPhaseOfMoon(Calendar cal)
Calculate the phase of the moon for a given date.

Code heavily influenced by hacklib.c in Nethack

The Algorithm:

     moon period = 29.53058 days ~= 30, year = 365.2422 days

     days moon phase advances on first day of year compared to preceding year
      = 365.2422 - 12 * 29.53058 ~= 11

     years in Metonic cycle (time until same phases fall on the same days of
      the month) = 18.6 ~= 19

     moon phase on first day of year (epact) ~= (11*(year%19) + 18) % 30
      (18 as initial condition for 1900)

     current phase in days = first day phase + days elapsed in year

     6 moons ~= 177 days
     177 ~= 8 reported phases * 22
     + 11 / 22 for rounding

Parameters:
  `cal` - the calendar.
Returns:
  The phase of the moon as a number between 0 and 7 with 0 meaning new moon and 4 meaning full moon.
Since:
  1.2, Ant 1.5

### getDateForHeader

public static String getDateForHeader()
Returns the current Date in a format suitable for a SMTP date header.

Returns:
  the current date.
Since:
  Ant 1.5.2

### parseDateFromHeader

public static Date parseDateFromHeader(String datestr) throws ParseException
Parses the string in a format suitable for a SMTP date header.

Parameters:
  `datestr` - string to be parsed
Returns:
  a java.util.Date object as parsed by the format.
Throws:
  `ParseException` - if the supplied string cannot be parsed by this pattern.
Since:
  Ant 1.8.0

### parseIso8601DateTime

public static Date parseIso8601DateTime(String datestr) throws ParseException
Parse a string as a datetime using the ISO8601_DATETIME format which is `yyyy-MM-dd'T'HH:mm:ss`

Parameters:
  `datestr` - string to be parsed
Returns:
  a java.util.Date object as parsed by the format.
Throws:
  `ParseException` - if the supplied string cannot be parsed by this pattern.
Since:
  Ant 1.6

### parseIso8601Date

public static Date parseIso8601Date(String datestr) throws ParseException
Parse a string as a date using the ISO8601_DATE format which is `yyyy-MM-dd`

Parameters:
  `datestr` - string to be parsed
Returns:
  a java.util.Date object as parsed by the format.
Throws:
  `ParseException` - if the supplied string cannot be parsed by this pattern.
Since:
  Ant 1.6

### parseIso8601DateTimeOrDate

public static Date parseIso8601DateTimeOrDate(String datestr) throws ParseException
Parse a string as a date using the either the ISO8601_DATETIME or ISO8601_DATE formats.

Parameters:
  `datestr` - string to be parsed
Returns:
  a java.util.Date object as parsed by the formats.
Throws:
  `ParseException` - if the supplied string cannot be parsed by either of these patterns.
Since:
  Ant 1.6

### parseLenientDateTime

public static Date parseLenientDateTime(String dateStr) throws ParseException
Parse a lenient ISO 8601, ms since epoch, or `<touch>`-style date. That is:

- Milliseconds since 1970-01-01 00:00
- `YYYY-MM-DD{T| }HH:MM[:SS[.SSS]][ ][±ZZ[[:]ZZ]]`
- `MM/DD/YYYY HH:MM[:SS] {AM|PM}`

where {a|b} indicates that you must choose one of a or b, and [c] indicates that you may use or omit c. ±ZZZZ is the timezone offset, and may be literally "Z" to mean GMT.

Parameters:
  `dateStr` - String
Returns:
  Date
Throws:
  `ParseException` - if date string does not match ISO 8601
Since:
  Ant 1.10.2