--add Date::Manip --add Date::Manip::DM6 are used (see the original post)

Yes, I saw that, if this was adequate, why do you have a problem?

You need to add more

Q: I have problem 
A: Use solution
Q: But I have problem already
[download]

perl -MDevel::VersionDump  -MDate::Manip::DM6 -MDate::Manip -e 1
...
Data::Dump                                        -    1.22
Date::Manip                                       -    6.43
Date::Manip::Base                                 -    6.43
Date::Manip::DM6                                  -    6.43
Date::Manip::Date                                 -    6.43
Date::Manip::Delta                                -    6.43
Date::Manip::Lang::english                        -    6.43
Date::Manip::Lang::index                          -    6.43
Date::Manip::Obj                                  -    6.43
Date::Manip::Recur                                -    6.43
Date::Manip::TZ                                   -    6.43
Date::Manip::TZ::etgmt00                          -    6.43
Date::Manip::TZ_Base                              -    6.43
Date::Manip::Zones                                -    6.43
...
[download]

$ scandeps -e " use Date::Manip::DM6 ; use Date::Manip ; "
[download]

964 modules here