Ante meridiem is commonly denoted as AM, am, a.m. or A.M. while post meridiem is usually abbreviated to PM, pm, p.m. or P.M. Each hour during the day, except midnight and noon, is suffixed by am or pm to identify whether the hour being referred to is in the morning, afternoon or evening.
Answer: The most common height for a bar top, whether it is a kitchen breakfast bar, a basement wet bar, or your commercial bar down at the corner pub is 42-inches. Standard conventions support the 42-inch bar height. Most premade back splashes are 4 to 6-inches tall.
I always recommend a standard height of 36 inches for kitchen islands as this is the most comfortable height to prep food at for the average person.