It’s a very common word and it has just lost it over time. It’s the same with the -g in jag for example. It’s almost always just å unless explicitly stressed. The -d is and is rarely pronounced in English either.
We only capitalize names, and we don't consider the words for nationalities, languages, days of the week, and months to be names. So they're only capitalized like any other word, at the start of a sentence.
Is it as common in Sweden to name children after the months of the year as it is in America? I've met people with the names of all months ranging from April to August. (Only a couple Julios for July in Spanish though).