Question

如何计算在两个日期之间开始的当天（整数）天/周/月/年？

日期以time函数提供的纪元秒提供。这些示例显示根据ISO 8601格式化的时间。

1 day begin  between 2014-08-24T23:59:59+0200 and 2014-08-25T00:00:01+0200   
0 day begins between 2014-08-25T00:00:01+0200 and 2014-08-25T23:59:59+0200

Answer 1

使用DateTime查找时间戳DT1和DT2之间的日/周/月/年开始次数，

查找DT1所属日/周/月/年的第一秒的时间戳。
查找DT2所属日/周/月/年的第一秒的时间戳。
查找这两个时间戳之间的天/周/月/年的差异。

use DateTime qw( );

# Or maybe << time_zone => 'local' >>?
my $dt1 = DateTime->from_epoch( epoch => ..., time_zone => '+0200' );
my $dt2 = DateTime->from_epoch( epoch => ..., time_zone => '+0200' );

# Some days in some time zones don't have a midnight, so switch to 'floating'.
# before truncating. The dts must all be in the same time zone beforehand.
my $date1 = $dt1->clone;
my $date2 = $dt2->clone;
$_->set_time_zone('floating')->truncate( to => 'day' )
   for $date1, $date2;

my $day_starts = $date2->delta_days($date1)->in_units('days');

my $week_starts = do {                   # Sunday starts
   my $date1_week_start = $date1->clone;
   my $date2_week_start = $date2->clone;

   $_->subtract( days => $_->day_of_week % 7 )
      for $date1_week_start, $date2_week_start;

   $date2_week_start->delta_days($date1_week_start)->in_units('weeks')
};

my $month_starts = do {
   my $date1_month_start = $date1->clone;
   my $date2_month_start = $date2->clone;

   $_->truncate( to => 'month' )
      for $date1_month_start, $date2_month_start;

   $date2_month_start->delta_md($date1_month_start)->in_units('months')
};

my $year_starts = abs( $date2->year - $date1->year );

printf("%d years, %d months, %d weeks and %d days begin between %s and %s\n",
   $year_starts,
   $month_starts,
   $week_starts,
   $day_starts,
   $date1->ymd,
   $date2->ymd,
);

my $dt1 = DateTime->new( year => 2014, month => 8, day => 23 );
my $dt2 = DateTime->new( year => 2014, month => 8, day => 24 );

给出

0 years, 0 months, 1 weeks and 1 days begin between 2014-08-23 and 2014-08-24

和

my $dt1 = DateTime->new( year => 2014, month => 1, day => 31 );
my $dt2 = DateTime->new( year => 2014, month => 2, day =>  1 );

给出

0 years, 1 months, 0 weeks and 1 days begin between 2014-01-31 and 2014-02-01

注意：

我认为有问题的日期之间没有任何日子丢失。
如果早期时间戳位于$dt1或$dt2，则无关紧要。

计算两个日期之间的天数/周/月/年

1 个答案: