Convert LDAP AccountExpires to DateTime in C#

Question

I want to convert 18 digit string from LDAP AccountExpires to Normal Date Time Format.

129508380000000000 >> May 26 2011

I got the above conversion from using the following link.

http://www.chrisnowell.com/information_security_tools/date_converter/Windows_active_directory_date_converter.asp?pwdLastSet,%20accountExpires,%20lastLogonTimestamp,%20lastLogon,%20and%20badPasswordTime

I tried to convert by using DateTime.Parse or Convert.ToDateTime. But no success.

Anyone know how to convert it? Thanks very much.

Answer 1

Some info for anyone who came here looking to set the AccountExpires value.

To clear the expiry is nice and easy:

entry.Properties["accountExpires"].Value = 0;

However if you try to directly write back an int64 / long:

entry.Properties["accountExpires"].Value = dt.ToFileTime();

You can get a 'COMException was unhandled - Unspecified error'

Instead write back the value as a string data type:

entry.Properties["accountExpires"].Value = dt.ToFileTime().ToString();

Be aware of the time of day you are setting, for consistancy with ADUC the time should be 00:00.

Instead of .Now or .UtcNow you can use .Today:

var dt1 = DateTime.Today.AddDays(90);
entry.Properties["accountExpires"].Value = dt1.ToFileTime().ToString();

Other input like dateTimePicker you can replace the time, Kind as Local for the Domain Controller:

var dt1 = dateTimePicker1.Value;
var dt2 = new DateTime(dt1.Year, dt1.Month, dt1.Day, 0, 0, 0, DateTimeKind.Local);
entry.Properties["accountExpires"].Value = dt2.ToFileTime().ToString();

Answer 2

Someone had the "best" way above but when it's set to never expired, the value is zero.

public static DateTime GetAccountExpiresDate(DirectoryEntry de)
{
    long expires = de.properties["accountExpires"].Value;
    if (expires == 0)   // doesn't expire
        return DateTime.MaxValue;

    return DateTime.FromFileTime(expires);
}

Answer 3

For Ruby

def ldapTimeConverter(ldap_time)
  Time.at((ldap_time/10000000)-11644473600)
end

Answer 4

If you View Source on the link you posted you should see a Javascript conversion algorithm that should translate quite nicely to c#

Answer 5

I stumbled across this working on a PowerShell script. I found I can query the accountexpirationdate property and no conversion is required.

Answer 6

Edited answer

It's the number of ticks since Jan-01-1601 in UTC, according to Reference, which describes the significance of the year 1601. Good background reading.

var accountExpires = 129508380000000000;
var dt = new DateTime(1601, 01, 01, 0, 0, 0, DateTimeKind.Utc).AddTicks(accountExpires);

Original Accepted Answer

It's the number of ticks since Jan-02-1601.

DateTime dt = new DateTime(1601, 01, 02).AddTicks(129508380000000000);