I'd say it's definitely needed (native UK-English speaker), the sentence sounds odd without it. Maybe things are different on the other side of the pond though...
I speak American English and that's how I always spell it as well. I'll likewise report it!
It's technically incorrect American English, but I remember commonly using it as well growing up not terribly far from the Canadian border. I suspect that the area around the U.S./Canadian border has some more fluid conventions than most of us are aware.
Dutch is a bit tricky here. Whether it is -d or -t depends on the infinitive. That is in this case reiZen. It does not matter that the z changes in several forms to s.
I explained it to me like this: when there is a specific time given (gisteren; vandaag; in this example: on monday) then Simple Past is fine (She traveled).