Task: Date manipulation


C++: #include <string>
#include <iostream>
#include <boost/date_time/local_time/local_time.hpp>
#include <sstream>
#include <boost/date_time/gregorian/gregorian.hpp>
#include <vector>
#include <boost/algorithm/string.hpp>
#include <cstdlib>
#include <locale>


int main( ) {
   std::string datestring ("March 7 2009 7:30pm EST" ) ;
   
   
   
   std::vector<std::string> elements ;
   
   boost::split( elements , datestring , boost::is_any_of( " " ) ) ;
   std::string datepart = elements[ 0 ] + " " + "0" + elements[ 1 ] + " " +
      elements[ 2 ] ; 
   std::string timepart = elements[ 3 ] ;
   std::string timezone = elements[ 4 ] ;
   const char meridians[ ] = { 'a' , 'p' } ;
   
   std::string::size_type found = timepart.find_first_of( meridians, 0 ) ;
   std::string twelve_hour ( timepart.substr( found , 1 ) ) ;
   timepart = timepart.substr( 0 , found ) ; 
   elements.clear( ) ;
   boost::split( elements , timepart , boost::is_any_of ( ":" ) ) ;
   long hour = std::atol( (elements.begin( ))->c_str( ) ) ;
   if ( twelve_hour == "p" ) 
      hour += 12 ;
   long minute = std::atol( ( elements.begin( ) + 1)->c_str( ) ) ; 
   boost::local_time::tz_database tz_db ;
   tz_db.load_from_file( "/home/ulrich/internetpages/date_time_zonespec.csv" ) ;
   
   boost::local_time::time_zone_ptr dyc = tz_db.time_zone_from_region( "America/New_York" ) ;
   
   boost::gregorian::date_input_facet *f =
      new boost::gregorian::date_input_facet( "%B %d %Y"  ) ;
   std::stringstream ss ;
   ss << datepart ;
   ss.imbue( std::locale( std::locale::classic( ) , f ) ) ;
   boost::gregorian::date d ;
   ss >> d ;
   boost::posix_time::time_duration td (  hour , minute , 0  ) ;
   
   
   boost::local_time::local_date_time lt ( d , td ,  dyc ,
	 boost::local_time::local_date_time::NOT_DATE_TIME_ON_ERROR ) ;
   std::cout << "local time: " << lt << '\n' ;
   ss.str( "" ) ;
   ss << lt ;
   
   boost::posix_time::time_duration td2 (12 , 0 , 0 , 0 ) ;
   boost::local_time::local_date_time ltlater = lt + td2 ; 
   boost::gregorian::date_facet *f2 =
      new boost::gregorian::date_facet( "%B %d %Y , %R %Z" ) ;
   std::cout.imbue( std::locale( std::locale::classic( ) , f2 ) ) ;
   std::cout << "12 hours after " << ss.str( )  << " it is " << ltlater << " !\n" ;
   
   boost::local_time::time_zone_ptr bt = tz_db.time_zone_from_region( "Europe/Berlin" ) ;
   std::cout.imbue( std::locale( "de_DE.UTF-8" ) ) ; 
   std::cout << "This corresponds to " << ltlater.local_time_in( bt ) << " in Berlin!\n" ;
   return 0 ;
}



Go: package main

import (
    "fmt"
    "time"
)

const taskDate = "March 7 2009 7:30pm EST"
const taskFormat = "January 2 2006 3:04pm MST"

func main() {
    if etz, err := time.LoadLocation("US/Eastern"); err == nil {
        time.Local = etz
    }
    fmt.Println("Input:             ", taskDate)
    t, err := time.Parse(taskFormat, taskDate)
    if err != nil {
        fmt.Println(err)
        return
    }
    t = t.Add(12 * time.Hour)
    fmt.Println("+12 hrs:           ", t)
    if _, offset := t.Zone(); offset == 0 {
        fmt.Println("No time zone info.")
        return
    }
    atz, err := time.LoadLocation("US/Arizona")
    if err == nil {
        fmt.Println("+12 hrs in Arizona:", t.In(atz))
    }
}