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Programming-Idioms

  • Perl
  • Lisp

Idiom #61 Get current date

Assign to the variable d the current date/time value, in the most standard type. 

(defparameter d
  (multiple-value-bind (seconds minutes hours day month year day-of-the-week daylight-savings-time-p time-zone)
(get-decoded-time)
(declare (ignorable day-of-the-week daylight-savings-time-p time-zone))
(format nil "~D-~2,'0D-~2,'0D ~2,'0D:~2,'0D:~2,'0D~%" year month day hours minutes seconds))
"The current date and time as a string value.")

GET-DECODED-TIME returns 9 values. We capture them all in MULTIPLE-VALUE-BIND. I chose to ignore day-of-the-week , daylight-savings-time-p , and time-zone , but they are still bound.
Note that Lisp's FORMAT specifier string is very different from most other languages!
$d = time;
$d = time;

my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime($d);

Builtin function time gets the number of seconds since epoch. localtime converts to date and time components and returns them as a list. For an OO interface, see Time::Piece.
use Time::Piece;

$d = localtime;		# local time as a Time::Piece object
say $d->ymd;		# yyyy-mm-dd format
say $d->datetime;	# ISO 8601 format

$g = gmtime;		# GMT as a Time::Piece object

Importing CPAN module Time::Piece replaces perl builtin functions localtime and gmtime with object-oriented equivalents.
with Ada.Calendar;
D : Ada.Calendar.Time := Ada.Calendar.Clock;
New implementation...
< > ⌨
programming-idioms.org 
(defparameter d
  (multiple-value-bind (seconds minutes hours day month year day-of-the-week daylight-savings-time-p time-zone)
(get-decoded-time)
(declare (ignorable day-of-the-week daylight-savings-time-p time-zone))
(format nil "~D-~2,'0D-~2,'0D ~2,'0D:~2,'0D:~2,'0D~%" year month day hours minutes seconds))
"The current date and time as a string value.")
$d = time;
$d = time;

my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime($d);
use Time::Piece;

$d = localtime;		# local time as a Time::Piece object
say $d->ymd;		# yyyy-mm-dd format
say $d->datetime;	# ISO 8601 format

$g = gmtime;		# GMT as a Time::Piece object
D : Ada.Calendar.Time := Ada.Calendar.Clock;
time_t d=time(0);
(def d #(java.util.Date.))
IDENTIFICATION DIVISION.
PROGRAM-ID. date.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 curr-date.
   03 year      pic 9(4).
   03 month     pic 9(2).
   03 day       pic 9(2).
PROCEDURE DIVISION.
   MOVE FUNCTION CURRENT-DATE TO curr-date
STOP RUN.
std::time_t d = std::time(nullptr);
DateTime d = DateTime.Now;
auto d = Clock.currTime;
var d = DateTime.now();

d = :calendar.local_time
D = calendar:local_time().
integer, dimension(8) :: d

call date_and_time (values=d)


d := time.Now()
d <- System.Posix.Time.epochTime

var d = Date.now();
var d = new Date();
long a = currentTimeMillis();
String d = "%tc".formatted(a);
Instant d = Instant.now();

Date a = getInstance().getTime();
String d = "%tc".formatted(a);
d = os.date()
NSDate *d=NSDate.date;
$d = time();
var
  _d: TDateTime;
begin
  _d := Now;
end.
d = datetime.datetime.now()
d = Time.now
let d = SystemTime::now();
let d = time::now();
Dim d As DateTime = DateTime.Now()