[ Operating System | The ECLiPSe Built-In Predicates | Reference Manual | Alphabetic Index ]

local_time_string(+UnixTime, +Format, -TimeString)

Create a string representation of the local time
UnixTime
Integer (seconds since 1/1/1970)
Format
String or Atom
TimeString
Variable or string

Description

This predicate converts UTC (Universal Coordinated Time, represented as 'Unix time', i.e. in seconds since 1970-01-01, 00:00) into a textual representation of the local time (taking into account time zone and daylight savings time settings), according to the given format string.

The format string is similar to the format string in the printf/2,3 predicate, but accepts different format specifiers. The exact set of format specifiers available depends on the underlying operating system (refer to the description of strftime()), but the following are generally available:

%a
Abbreviated weekday name for current locale
%A
Full weekday name for current locale
%b
Abbreviated month name for current locale
%B
Full month name for current locale
%c
Preferred date and time representation for current locale
%d
Day of month as decimal number (01-31)
%H
Hour in 24-hour format (00-23)
%I
Hour in 12-hour format (01-12)
%j
Day of year as decimal number (001-366)
%m
Month as decimal number (01-12)
%M
Minute as decimal number (00-59)
%p
Current locale's A.M./P.M. indicator for 12-hour clock
%S
Second as decimal number (00-59)
%U
Week of year (00-53), with first Sunday first day of week 01
%w
Weekday as decimal number (0-6, Sunday is 0)
%W
Week of year (00-53), with first Monday first day of week 01
%x
Date representation for current locale
%X
Time representation for current locale
%y
Year without century, as decimal number (00-99)
%Y
Year with century, as decimal number
%Z
Time-zone name or abbreviation, empty if time zone is unknown
%%
Percent sign

This predicate is based on POSIX strftime().

Modes and Determinism

Exceptions

(4) instantiation fault
UnixTime or Format are uninstantiated
(5) type error
UnixTime, Format or TimeString are instantiated, but not strings

Examples

    ?- get_flag(unix_time, T), local_time_string(T, "%c", S).
    T = 1049564174
    S = "Sat Apr 05 18:36:14 2003"
    Yes (0.00s cpu)

    ?- get_flag(unix_time, T),
	     local_time_string(T, "We write the year %Y in time zone %Z", S).
    T = 1049564247
    S = "We write the year 2003 in time zone BST"
    Yes (0.00s cpu)

See Also

date / 1, local_time / 8, library(calendar)