官方网址：http://search.cpan.org/~stbey/Date-Calc-6.3/lib/Date/Calc.pod#___top
use Date::Calc qw( Days_in_Year Days_in_Month Weeks_in_Year leap_year check_date check_time check_business_date Day_of_Year Date_to_Days Day_of_Week Week_Number Week_of_Year Monday_of_Week Nth_Weekday_of_Month_Year Standard_to_Business Business_to_Standard Delta_Days Delta_DHMS Delta_YMD Delta_YMDHMS N_Delta_YMD N_Delta_YMDHMS Normalize_DHMS Add_Delta_Days Add_Delta_DHMS Add_Delta_YM Add_Delta_YMD Add_Delta_YMDHMS Add_N_Delta_YMD Add_N_Delta_YMDHMS System_Clock Today Now Today_and_Now This_Year Gmtime Localtime Mktime Timezone Date_to_Time Time_to_Date Easter_Sunday Decode_Month Decode_Day_of_Week Decode_Language Decode_Date_EU Decode_Date_US Fixed_Window Moving_Window Compress Uncompress check_compressed Compressed_to_Text Date_to_Text Date_to_Text_Long English_Ordinal Calendar Month_to_Text Day_of_Week_to_Text Day_of_Week_Abbreviation Language_to_Text Language Languages Decode_Date_EU2 Decode_Date_US2 Parse_Date ISO_LC ISO_UC ); use Date::Calc qw(:all); Days_in_Year $days = Days_in_Year($year,$month); Days_in_Month $days = Days_in_Month($year,$month); Weeks_in_Year $weeks = Weeks_in_Year($year); leap_year if (leap_year($year)) check_date if (check_date($year,$month,$day)) check_time if (check_time($hour,$min,$sec)) check_business_date if (check_business_date($year,$week,$dow)) Day_of_Year $doy = Day_of_Year($year,$month,$day); Date_to_Days $days = Date_to_Days($year,$month,$day); Day_of_Week $dow = Day_of_Week($year,$month,$day); Week_Number $week = Week_Number($year,$month,$day); # DEPRECATED Week_of_Year ($week,$year) = Week_of_Year($year,$month,$day); # RECOMMENDED $week = Week_of_Year($year,$month,$day); # DANGEROUS Monday_of_Week ($year,$month,$day) = Monday_of_Week($week,$year); Nth_Weekday_of_Month_Year if (($year,$month,$day) = Nth_Weekday_of_Month_Year($year,$month,$dow,$n)) Standard_to_Business ($year,$week,$dow) = Standard_to_Business($year,$month,$day); Business_to_Standard ($year,$month,$day) = Business_to_Standard($year,$week,$dow); Delta_Days $Dd = Delta_Days($year1,$month1,$day1, $year2,$month2,$day2); Delta_DHMS ($Dd,$Dh,$Dm,$Ds) = Delta_DHMS($year1,$month1,$day1, $hour1,$min1,$sec1, $year2,$month2,$day2, $hour2,$min2,$sec2); Delta_YMD ($Dy,$Dm,$Dd) = Delta_YMD($year1,$month1,$day1, $year2,$month2,$day2); Delta_YMDHMS ($D_y,$D_m,$D_d, $Dh,$Dm,$Ds) = Delta_YMDHMS($year1,$month1,$day1, $hour1,$min1,$sec1, $year2,$month2,$day2, $hour2,$min2,$sec2); N_Delta_YMD ($Dy,$Dm,$Dd) = N_Delta_YMD($year1,$month1,$day1, $year2,$month2,$day2); N_Delta_YMDHMS ($D_y,$D_m,$D_d, $Dhh,$Dmm,$Dss) = N_Delta_YMDHMS($year1,$month1,$day1, $hour1,$min1,$sec1, $year2,$month2,$day2, $hour2,$min2,$sec2); Normalize_DHMS ($Dd,$Dh,$Dm,$Ds) = Normalize_DHMS($Dd,$Dh,$Dm,$Ds); Add_Delta_Days ($year,$month,$day) = Add_Delta_Days($year,$month,$day, $Dd); Add_Delta_DHMS ($year,$month,$day, $hour,$min,$sec) = Add_Delta_DHMS($year,$month,$day, $hour,$min,$sec, $Dd,$Dh,$Dm,$Ds); Add_Delta_YM ($year,$month,$day) = Add_Delta_YM($year,$month,$day, $Dy,$Dm); Add_Delta_YMD ($year,$month,$day) = Add_Delta_YMD($year,$month,$day, $Dy,$Dm,$Dd); Add_Delta_YMDHMS ($year,$month,$day, $hour,$min,$sec) = Add_Delta_YMDHMS($year,$month,$day, $hour,$min,$sec, $D_y,$D_m,$D_d, $Dh,$Dm,$Ds); Add_N_Delta_YMD ($year,$month,$day) = Add_N_Delta_YMD($year,$month,$day, $Dy,$Dm,$Dd); Add_N_Delta_YMDHMS ($year,$month,$day, $hour,$min,$sec) = Add_N_Delta_YMDHMS($year,$month,$day, $hour,$min,$sec, $D_y,$D_m,$D_d, $Dhh,$Dmm,$Dss); System_Clock ($year,$month,$day, $hour,$min,$sec, $doy,$dow,$dst) = System_Clock([$gmt]); Today ($year,$month,$day) = Today([$gmt]); Now ($hour,$min,$sec) = Now([$gmt]); Today_and_Now ($year,$month,$day, $hour,$min,$sec) = Today_and_Now([$gmt]); This_Year $year = This_Year([$gmt]); Gmtime ($year,$month,$day, $hour,$min,$sec, $doy,$dow,$dst) = Gmtime([time]); Localtime ($year,$month,$day, $hour,$min,$sec, $doy,$dow,$dst) = Localtime([time]); Mktime $time = Mktime($year,$month,$day, $hour,$min,$sec); Timezone ($D_y,$D_m,$D_d, $Dh,$Dm,$Ds, $dst) = Timezone([time]); Date_to_Time $time = Date_to_Time($year,$month,$day, $hour,$min,$sec); Time_to_Date ($year,$month,$day, $hour,$min,$sec) = Time_to_Date([time]); Easter_Sunday ($year,$month,$day) = Easter_Sunday($year); Decode_Month if ($month = Decode_Month($string[,$lang])) Decode_Day_of_Week if ($dow = Decode_Day_of_Week($string[,$lang])) Decode_Language if ($lang = Decode_Language($string)) Decode_Date_EU if (($year,$month,$day) = Decode_Date_EU($string[,$lang])) Decode_Date_US if (($year,$month,$day) = Decode_Date_US($string[,$lang])) Fixed_Window $year = Fixed_Window($yy); Moving_Window $year = Moving_Window($yy); Compress $date = Compress($year,$month,$day); Uncompress if (($century,$year,$month,$day) = Uncompress($date)) check_compressed if (check_compressed($date)) Compressed_to_Text $string = Compressed_to_Text($date[,$lang]); Date_to_Text $string = Date_to_Text($year,$month,$day[,$lang]); Date_to_Text_Long $string = Date_to_Text_Long($year,$month,$day[,$lang]); English_Ordinal $string = English_Ordinal($number); Calendar $string = Calendar($year,$month[,$orthodox[,$lang]]); Month_to_Text $string = Month_to_Text($month[,$lang]); Day_of_Week_to_Text $string = Day_of_Week_to_Text($dow[,$lang]); Day_of_Week_Abbreviation $string = Day_of_Week_Abbreviation($dow[,$lang]); Language_to_Text $string = Language_to_Text($lang); Language $lang = Language(); Language($lang); # DEPRECATED $oldlang = Language($newlang); # DEPRECATED Languages $max_lang = Languages(); Decode_Date_EU2 if (($year,$month,$day) = Decode_Date_EU2($string[,$lang])) Decode_Date_US2 if (($year,$month,$day) = Decode_Date_US2($string[,$lang])) Parse_Date if (($year,$month,$day) = Parse_Date($string[,$lang])) ISO_LC $lower = ISO_LC($string); ISO_UC $upper = ISO_UC($string); Version $string = Date::Calc::Version();