Is "am" redundant?

First, "windows is opened" is a glaring error. Windows being plural, the verb form for that should be "are." The use of a.m. (as it is rendered in American usage) might be considered redundant, as morning is specified. Repetition is common in the language, and is a relic dating back to Anglo-Saxon, or Old English. So, it is not wrong, nor would such a usage be uncommon. Perhaps it is redundant, but that's not necessarily a problem in English.

Thanks, Setanta.

I would use 9 a.m. instead of 9am.

The windows are opened every morning at nine.