The following lines are probably missing in the danish .po-file (these are in Swedish, you have to change them to Danish):
#: bb-includes/functions.bb-core.php:385
#, php-format
msgid "%d year"
msgid_plural "%d years"
msgstr[0] "%d år"
msgstr[1] "%d år"
#: bb-includes/functions.bb-core.php:386
#, php-format
msgid "%d month"
msgid_plural "%d months"
msgstr[0] "%d månad"
msgstr[1] "%d månader"
#: bb-includes/functions.bb-core.php:387
#, php-format
msgid "%d week"
msgid_plural "%d weeks"
msgstr[0] "%d vecka"
msgstr[1] "%d veckor"
#: bb-includes/functions.bb-core.php:388
#, php-format
msgid "%d day"
msgid_plural "%d days"
msgstr[0] "%d dag"
msgstr[1] "%d dagar"
#: bb-includes/functions.bb-core.php:389
#, php-format
msgid "%d hour"
msgid_plural "%d hours"
msgstr[0] "%d timme"
msgstr[1] "%d timmar"
#: bb-includes/functions.bb-core.php:390
#, php-format
msgid "%d minute"
msgid_plural "%d minutes"
msgstr[0] "%d minut"
msgstr[1] "%d minuter"
#: bb-includes/functions.bb-core.php:391
#, php-format
msgid "%d second"
msgid_plural "%d seconds"
msgstr[0] "%d sekund"
msgstr[1] "%d sekunder"
