Getting the century only from a year

[Doug]

Is there a format that can be used in DateTime.ToString() that will
allow you to get only the century of a given year. "yy" of course
doesn't work, that returns the year itself, not the century.

[Paul E Collins]

"Doug" <dn******@dtgnet.com> wrote:

Is there a format that can be used in DateTime.ToString()
that will allow you to get only the century of a given year.
"yy" of course doesn't work, that returns the year itself,
not the century.

Well, get the full year that way, extract the first two digits of the
year (e.g. "19" from "1984"), and add one (since 19xx is in the 20th
century, for example).

string firstTwoDigits = yearString.Substring(0, 2);
int century = Convert.ToInt32(firstTwoDigits) + 1;

You don't have to worry about years with fewer than two digits,
because years before about 1750 aren't supported. (That's when the
modern Gregorian calendar came into force.)

Eq.

[Lars-Inge Tønnessen \(VJ# MVP\)]

It could be nice to have the century before the Gregorian calender too. :o)

using System;
using System.Collections.Generic;
using System.Text;

namespace Century
{
class Program
{

public int Cent(int year)
{
if (year.ToString().Length == 1)
return 1;
else if (year.ToString().Length == 2)
return 1;
else if (year.ToString().Length == 3)
return (Convert.ToInt32(year.ToString().Substring(0, 1))) +
1;
else if (year.ToString().Length == 4)
return (Convert.ToInt32(year.ToString().Substring(0, 2))) +
1;
else
return -1;
}

public Program()
{
System.Console.WriteLine("" + Cent(1));
System.Console.WriteLine("" + Cent(13));
System.Console.WriteLine("" + Cent(171));
System.Console.WriteLine("" + Cent(1714));
System.Console.WriteLine("" + Cent(2006));
System.Console.ReadKey();
}

static void Main(string[] args)
{
new Program();
}
}
}
Regards,
Lars-Inge Tønnessen

[Doug]

There's no way to use a format string of some kind? Like you can use
MM for month and yy for year and so on, there's nothing to represent
just the century?

[Paul E Collins]

"Doug" <dn******@dtgnet.com> wrote:

There's no way to use a format string of some kind?
Like you can use MM for month and yy for year and
so on, there's nothing to represent just the century?

That's correct. Look up "DateTimeFormatInfo" in the Visual Studio help
file, if you have it. That will show you the complete list, with no
option for centuries.

Eq.

[Michael Bray]

"Paul E Collins" <fi******************@CL4.org> wrote in news:dvpspf$6mo$1
@nwrdmz03.dmz.ncs.ea.ibs-infra.bt.com:

Well, get the full year that way, extract the first two digits of the
year (e.g. "19" from "1984"), and add one (since 19xx is in the 20th
century, for example).

string firstTwoDigits = yearString.Substring(0, 2);
int century = Convert.ToInt32(firstTwoDigits) + 1;

Why not just (dtDateTimeVar.Year / 100) + 1 ?

-mdb