I asked my boyfriend to give me the guy's perspective on this, and he said he thinks six months should be the standard minimum too.
So at the end of the day, can you ever truly know if a relationship (or marriage) is going to work? But you know that you're absolutely, positively crazy about someone, faults and all.
Oh, and you can know what those faults are and enter into a marriage with open eyes about who you're really marrying. Here are some things that I think should happen before you decide to get engaged, regardless of how long it's been:—You should say "I love you" to one another, and mean it.—You should meet close friends and family members.—You should experience some sort of conflict to see how you both react to stress.—You should disagree about something.—You should know your partner's core as a person.—You should discuss your ideas about money, gender roles, and where you want to live.—You should feel in your gut that you can trust this person.—You should both come first to one another.—You should be able to speak openly and feel respected at all times.—You should feel comfortable about your sexual compatibility and both feel satisfied.
I think that anecdotally, people around me would expect a couple to live together or at least date regularly for a couple of years before announcing an engagement.
If they hadn't done so, people would say things like "they haven't lived together very long, I hope they know what they're doing". I think people in my community believe that it is better to let the 2-year "honeymoon phase" of crazy love wear out a bit, so that the couple can see how cohesive they are without all that help from mother nature, before committing to a lifetime together.
And you can discuss your values, and goals, and hopes and dreams, and both have the intention to stick things out if you run into trouble (which, in my opinion, is what marriage is all about vs. That said, is a month too soon to decide to commit to someone for life? I tend to think that achieving all of those things usually takes six months (at the least).