中获得周第一天的星期一25/07/2011
例如今天是2011年7月28日我如何在ruby
>> Date.today.beginning_of_week.strftime('%d/%m/%Y')
#=> 25/07/2011
查看Rails下的Time和Date类了解更多信息,strftime类了解有关格式化选项的信息。
没有Rails/activessupport:
phrogz$ irb
> require 'date'
> now = Date.today
#=> #<Date: 2011-07-28 (4911541/2,0,2299161)>
> sunday = now - now.wday
#=> #<Date: 2011-07-24 (4911533/2,0,2299161)>
> monday = now - (now.wday - 1) % 7
#=> #<Date: 2011-07-25 (4911535/2,0,2299161)>
> monday.iso8601
#=> "2011-07-25"
> monday.strftime('%d/%m/%Y')
#=> "25/07/2011"
更多信息,参见标准库中的Date
类。
封装成一个方法:
require 'date'
# For weekdays to start on Monday use 1 for the offset; for Tuesday use 2, etc.
def week_start( date, offset_from_sunday=0 )
date - (date.wday - offset_from_sunday)%7
end
sun = Date.parse '2011-07-24'
week_start(sun,0).strftime('%a, %b-%d') #=> "Sun, Jul-24"
week_start(sun,1).strftime('%a, %b-%d') #=> "Mon, Jul-18"