what is being reported now as totals are actually composites of previous days finally being tallied
I'm getting that same belief nowadays. The thing is though, what does it matter? We have absolutely no control over earnings accumulation and no idea what rules G is applying. More importantly, we never will be involved or have any knowledge in the process.
Yes, it's important to check earnings regularly just in case it indicates a problem such as a site going down or some infringement of the rules. But if both of those can be ruled it, all we can do is sit back and watch. One day's earnings is no longer relevant, at best a week's earnings are an indicator of performance or maybe even a month is best.
Another view might be that Adwords users are becoming far more sophisticated in their targeting of ads. Weather, holidays, economic conditions may well affect Adwords users to target ads to appear in very specific time frames and conditions. This could well account for significant variations of earnings day by day and even hour by hour.