The subject of how many days our loved ones can spend outside the UK whilst here on a settlement visa has cropped up many times on the forum. The link below answers many of our questions regarding this subject, included in the article is a link to a official Government website which details how the days and absences are calculated for certain visa types. http://lifeintheuk.net/index.php/after_the_test/absences_during_residence_ilr/ In a nutshell you are allowed 90 days per calendar year and extensions for family illness, work and natural disasters. The Government information gives a list of documents that can be submitted as proof of legitimate extended periods outside the UK.
@Timmers, thank you so much for digging this information! This gave me a peace of mind. Thank you again!