I wanted to find the lightest watch available that tells time, has a calendar, and is under $50 or so. I found that Casio has a large selection in that range, and their cheaper watches are known for being high quality considering the price point.
I’m attaching an Excel spreadsheet with the data I collected: CasioWatches
I’m leaning toward the Casio Men’s Sport Watch, because it is very light at just 0.74 ounces, and also has an analog display. The MQ24-7B2 weighs even less, at 0.63 ounces, but its face is not luminous, and it doesn’t have a calendar. It looks like I will have to reset the calendar on the Casio Men’s Sport Watch each month, because it isn’t perpetual. Analog watches with a perpetual calendar tend to be more expensive, ranging from ~$150 and up. Seiko appears to be a quality brand offering such perpetual watches. However, even those entry range watches tend to be much heavier and larger, and their cases are made of steel. A steel case would be cool, but I want to try a watch that is extremely light.