Keep/ Change Colnames via a specific pattern

could you help me with this little problem:

My colnames look like :

...
    [121] "14.11.1838"      "21.11.1838"      "30.11.1838"      "07.12.1838.1"      "14.12.1838"     
    [126] "21.12.1838"      "NA"              "31.12.1838"      "01.01.1839"      "02.01.1839"     
    [131] "03.01.1839"      "04.01.1839"      "NA.1"      "07.01.1839.1"      "08.01.1839"     
....

In total I have more than 500 names. Now I want to delete all the ".1" when they are at the end of a name (date). And I want to delete all names (the hole column) containg "NA"

Thanks