Selecting the last two dates

[Developer1]

I am relatively new to cognos, but I am familiar with the maximum function in trying to identify the most recent date of a client's record.  For instance;

maximum ([Date] for [Client Account])

Is there a similar function (or a way to get) the two most recent dates in a relational database?

The data look like;
Client Account    Date
1234                 1/12/2019
1234                 1/15/2019
1234                 2/21/2019
1235                 1/11/2019
1235                 1/14/2019
1235                 1/21/2019

So, for Client Accounts 1234 and 1235, I only want to select the two most recent dates (1/12/2019 and 1/15/2019 for client 1234 and 1/11/2019 and 1/14/2019 for client 1235)

Any help would be appreciated.

[BigChris]

I'm not sure that I've used it with dates, but you might be able to do something with the rank function. So something like:

rank([Date] for [Client Account]) <= 2

[Developer1]

Thanks, BigChris.  The rank function is new to me.  It works great!  If I include the <=2, it returns a '1' for the last two dates and a '0' for everything else.  If I leave off the <=2, it provides a nice ranking of the dates, '1', '2', '3'...for the most recent date, the 2nd most recent date, and the 3rd most recent date, etc.

Thank you!