If you are using CrmService's Create or Update methods perhaps you already noticed that when you send a date in the DD-MM-YYYY HH:MM:SS format CrmService will read this date as MM-DD-YYYY HH:MM:SS and that's what he'll write to your MSCRM db.
So if you're writing a contact's birthdate/birthday like "24-07-1980 00:00:00" CRM will throw an exception because he's using "24" as MM and "07" as DD when he shouldn't. You need a workaround such as your own fixDate() method. The following fixDate() method was created by Marco Silva, member of my MS CRM Dynamics 4.0 project team of two (me and him). This method gets something like "24-07-1980 00:00:00" and returns it in a CRM friendly format "07-24-1980 21:00:00". If you check your MS CRM db you will see the correct date but perhaps not the correct time "24-07-1980 20:00:00".
private static string fixDate(String date)
string day = data.Substring(0, 2);
string month = data.Substring(3, 2);
string year = data.Substring(6, 4);
string hour = "21";
string min = "00";
string sec = "00";
return month + "-" + day + "-" + year + " " + hour + ":" + min + ":" + sec;
You may notice that we're forcing the hour, minutes and seconds and there's a pretty good explanation for that. The explanation is related with Time Zone handling issues that affect MS CRM 4 (and 3). My time zone settings (MS CRM server, SQL server, desktop) are all GMT (...Lisbon). Some specific datetimes (not all) are written to MS CRM DB with less an hour and that makes them go back one day.
If you send "24-07-1980 00:00:00" or "07-24-1980 00:00:00" to be more accurate to your CrmService it will write "23-07-1990 23:00:00" to MS CRM db! Ooops! Wrong birthdate! However if you check your contact's file you will see "24-07-1980". However the MS CRM db birthdate datetime is wrong ("23-07-1990 23:00:00") and you can't export it to an external db such as a datawarehouse. The workaround for this one requires two different approaches: a CrmService approach and an onSave approach (to fix typed birthdates).
Both of these workarounds require you to change birthdate's time to something bigger than "01:00:00" because if the CrmService "steals" you one hour it won't "steal" you a whole day! I chose to set "21:00:00" as my "fake" time. So, if I send this CrmService friendly "fake" date "07-24-1980 21:00:00" to CrmService he will write "24-07-1980 20:00:00" to MS CRM db! And that works for me as the birthdate time isn't important (or visible). So my first workaround also is solved by the fixDate() method above. The second workaround has to be properly included inside the onSave event which you have to enable.
This workaround was provided by Pedro Pereira who helped me fix this issue for MS CRM 3.0 but it works fine with MS CRM 4.0.