Program to convert time from 12 hour to 24 hour format
Given a time at 12-hour AM/PM format, convert it to military (24-hour) time.
Note: Midnight is 12:00:00 AM on a 12-hour clock and 00:00:00 on a 24-hour clock. Noon is 12:00:00 PM on 12-hour clock and 12:00:00 on 24-hour clock
Examples:
Input : A single string containing a time in 12-hour
clock format(hh:mm:ss AM or hh:mm:ss PM
where 01 <= hh <= 12 or 01 <= mm,ss <= 59
Output :Convert and print the given time in 24-hour format,
where 00 <= hh <= 23
Input : 07:05:45PM
Output : 19:05:45
C++
#include<iostream>
using namespace std;
void print24(string str)
{
int h1 = ( int )str[1] - '0' ;
int h2 = ( int )str[0] - '0' ;
int hh = (h2 * 10 + h1 % 10);
if (str[8] == 'A' )
{
if (hh == 12)
{
cout << "00" ;
for ( int i=2; i <= 7; i++)
cout << str[i];
}
else
{
for ( int i=0; i <= 7; i++)
cout << str[i];
}
}
else
{
if (hh == 12)
{
cout << "12" ;
for ( int i=2; i <= 7; i++)
cout << str[i];
}
else
{
hh = hh + 12;
cout << hh;
for ( int i=2; i <= 7; i++)
cout << str[i];
}
}
}
int main()
{
string str = "07:05:45PM" ;
print24(str);
return 0;
}
|
Java
import java.io.*;
public class GFG
{
static void print24(String str)
{
int h1 = ( int )str.charAt( 1 ) - '0' ;
int h2 = ( int )str.charAt( 0 ) - '0' ;
int hh = (h2 * 10 + h1 % 10 );
if (str.charAt( 8 ) == 'A' )
{
if (hh == 12 )
{
System.out.print( "00" );
for ( int i = 2 ; i <= 7 ; i++)
System.out.print(str.charAt(i));
}
else
{
for ( int i = 0 ; i <= 7 ; i++)
System.out.print(str.charAt(i));
}
}
else
{
if (hh == 12 )
{
System.out.print( "12" );
for ( int i = 2 ; i <= 7 ; i++)
System.out.print(str.charAt(i));
}
else
{
hh = hh + 12 ;
System.out.print(hh);
for ( int i = 2 ; i <= 7 ; i++)
System.out.print(str.charAt(i));
}
}
}
public static void main (String[] args)
{
String str = "07:05:45PM" ;
print24(str);
}
}
|
Python3
def print24(s):
h1 = ord (s[ 1 ]) - ord ( '0' )
h2 = ord (s[ 0 ]) - ord ( '0' )
hh = (h2 * 10 + h1 % 10 )
if (s[ 8 ] = = 'A' ):
if (hh = = 12 ):
print ( '00' , end = '')
for i in range ( 2 , 8 ):
print (s[i], end = '')
else :
for i in range ( 0 , 8 ):
print (s[i], end = '')
else :
if (hh = = 12 ):
print ( "12" , end = '')
for i in range ( 2 , 8 ):
print (s[i], end = '')
else :
hh = hh + 12 ;
print (hh, end = '')
for i in range ( 2 , 8 ):
print (s[i], end = '')
if __name__ = = "__main__" :
s = "07:05:45PM"
print24(s)
|
C#
using System;
class GFG
{
static void print24(String str)
{
int h1 = ( int )str[1] - '0' ;
int h2 = ( int )str[0] - '0' ;
int hh = (h2 * 10 + h1 % 10);
if (str[8] == 'A' )
{
if (hh == 12)
{
Console.Write( "00" );
for ( int i = 2; i <= 7; i++)
Console.Write(str[i]);
}
else
{
for ( int i = 0; i <= 7; i++)
Console.Write(str[i]);
}
}
else
{
if (hh == 12)
{
Console.Write( "12" );
for ( int i = 2; i <= 7; i++)
Console.Write(str[i]);
}
else
{
hh = hh + 12;
Console.Write(hh);
for ( int i = 2; i <= 7; i++)
Console.Write(str[i]);
}
}
}
public static void Main(String[] args)
{
String str = "07:05:45PM" ;
print24(str);
}
}
|
Javascript
<script>
function print24(str)
{
var h1 = Number(str[1] - '0' );
var h2 = Number(str[0] - '0' );
var hh = (h2 * 10 + h1 % 10);
if (str[8] == 'A' )
{
if (hh == 12)
{
document.write( "00" );
for ( var i = 2; i <= 7; i++)
document.write(str[i]);
}
else
{
for ( var i = 0; i <= 7; i++)
document.write(str[i]);
}
}
else
{
if (hh == 12)
{
document.write( "12" );
for ( var i = 2; i <= 7; i++)
document.write(str[i]);
}
else
{
hh = hh + 12;
document.write(hh);
for ( var i = 2; i <= 7; i++)
document.write(str[i]);
}
}
}
var str = "07:05:45PM" ;
print24(str);
</script>
|
Time Complexity: O(1)
Auxiliary Space: O(1)
Method 2: Using java Date
C++
#include <iostream>
#include <ctime>
using namespace std;
string englishTime(string input)
{
struct tm tm ;
strptime(input.c_str(), "%I:%M:%S %p" , & tm );
char output[9];
strftime (output, sizeof (output), "%H:%M:%S" , & tm );
return string(output);
}
int main() {
cout << englishTime( "07:05:45 PM" ) << endl;
return 0;
}
|
Java
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
public class GFG {
public static String englishTime(String input)
throws ParseException
{
DateFormat dateFormat
= new SimpleDateFormat( "hh:mm:ss aa" );
DateFormat format
= new SimpleDateFormat( "HH:mm:ss" );
Date time = null ;
String output = "" ;
time = dateFormat.parse(input);
output = format.format(time);
return output;
}
public static void main(String[] arg)
throws ParseException
{
System.out.println(englishTime( "07:05:45 PM" ));
}
}
|
Python3
import datetime
def englishTime( input ):
dateFormat = datetime.datetime.strptime( input , "%I:%M:%S %p" )
format = datetime.datetime.strftime(dateFormat, "%H:%M:%S" )
return format
print (englishTime( "07:05:45 PM" ))
|
C#
using System;
using System.Globalization;
class GFG {
public static string englishTime( string input)
{
DateTime time;
CultureInfo provider = CultureInfo.InvariantCulture;
DateTime.TryParseExact(input, "hh:mm:ss tt" , provider, DateTimeStyles.None, out time);
DateTimeFormatInfo dtfi = CultureInfo.InvariantCulture.DateTimeFormat;
string output = time.ToString( "HH:mm:ss" , dtfi);
return output;
}
static void Main( string [] args) {
Console.WriteLine(englishTime( "07:05:45 PM" ));
}
}
|
Javascript
function englishTime(input) {
let date = new Date( "1970-01-01 " + input);
let format = date.toLocaleTimeString([], { hour12: false });
return format;
}
console.log(englishTime( "07:05:45 PM" ));
|
Time Complexity: O(1)
Auxiliary Space: O(1)
Last Updated :
10 Apr, 2023
Like Article
Save Article
Share your thoughts in the comments
Please Login to comment...