Dimery,

What version of the program are you using?

What are your date settings under Setup, Settings, Company, Information?

Have you activated the option Setup, Settings, Company, System, Do not allow transactions dated before xxxxx?  If so, what date is there?

Do you have the Allow transactions in the future option turned off on the same dialog?

Edit: What date format are you using in Sage 50 and what date format are you using in Windows?

One more.

Also can you activate four-digit years in Sage 50 and let us know if the century is still 20xx in the messages?

How do you do this?  Settings?

Setup, Settings, Company, Date Format.

Yes, I've done that, already MM dd yyyy, 4 digits.  

Oh wait, after changing the date for the long format, it worked.  Thank you Mr. Ridings!  Happy New Year.  

worked for me too!!!! Thank you!!

Great, glad you both have it working.  Now for greater clarity because I am expecting a lot of other people to have the same issue, can you define what you mean by

Aaron Kent said:

after changing the date for the long format

See the image below.  Are you talking about the Short Date format with a four-digit year or are you really talking about the Long Date Format in the image below?

Need to go to settings, setup, company, date format,  then in both dates, long form and short form, both have to be four digit year yyyy.  That should do it. 

I followed your instructions;

1. Settings

2. Company

3.Date Format

4. Changed Long date from 01/01/2021 to 01 JAN 2021

5. changed both screen use and report use to "long dates" as well.

My screen looks different then yours but my program is probably older. 

The image I posted is the date formats in Windows, not Sage 50.  If you didn't change anything in Windows, that's ok.

My problem is that I can't replicate your issue so I can't tell Sage what might be causing the problem so they can fix it however there are others with the same problem over the last couple of days.  The Long Date format can never be 01/01/2021 as you have indicated.  By definition, Long Date includes the words for the month.  I don't know if you were using MM/dd/yy for your short date or dd/MM/yy for it.  If you are running an older version, then that might have been good information to give us so we can help you.  Sage will not update older versions for this kind of thing.

What is your Windows date formats according to your Regional Settings in the Control panel (similar to the image I posted above)?

This set up below currently works on Sage 50 Pro 2021.1 with a session date of Jan 1, 2021, latest transaction date of Jan 7, 2021.  My system is Win7Pro so it may be a Win8, 8.1 or 10 issue if it's happening in the 2021 version.

The image I posted is the date formats in Windows, not Sage 50.  If you didn't change anything in Windows, that's ok.

My problem is that I can't replicate your issue so I can't tell Sage what might be causing the problem so they can fix it however there are others with the same problem over the last couple of days.  The Long Date format can never be 01/01/2021 as you have indicated.  By definition, Long Date includes the words for the month.  I don't know if you were using MM/dd/yy for your short date or dd/MM/yy for it.  If you are running an older version, then that might have been good information to give us so we can help you.  Sage will not update older versions for this kind of thing.

What is your Windows date formats according to your Regional Settings in the Control panel (similar to the image I posted above)?

This set up below currently works on Sage 50 Pro 2021.1 with a session date of Jan 1, 2021, latest transaction date of Jan 7, 2021.  My system is Win7Pro so it may be a Win8, 8.1 or 10 issue if it's happening in the 2021 version.

I did not change anything in windows

OK thanks.  I should also mention that we had already posted entries in our office in 2013.2 and never saw the issue because we run all our files on four-digit years which I believe is the default setting.