What's a good, generic name for chart of things by time of day? We're creating a chart showing traffic by time of day over a given period. So the y-axis is traffic, the x-axis is midnight, 1am, 2am, etc. It could also be days of the week. What's the generic name for this type of chart? I've come up with "cycle chart". Is that the standard? Is there one?

Update:
Just to add a bit more clarity, what's being shown in the top chart is not one day, it's an aggregation of many days. E.g. over the last month, 6am has on average been lower than noon. Similarly, in the bottom chart, over the last year, traffic dips on Saturdays.
 A: Nick Cox (Stata Journal 2006, p403) calls this sort of plot a 'cycle plot', but notes that:

Cycle plots have been discussed under other names in the literature, including cycle-subseries plot, month plot, seasonal-by-month plot, and seasonal subseries plot.

(followed by a load of refs to textbooks and papers)
Many of these are clearly specific to seasonality, i.e. periods of one year. I still like the suggestion of 'periodic plot/chart' that I made in a comment to the question, but it appears the questioner's original suggestion of 'cycle plot/chart' is in fact the more standard generic term.
A: What you've illustrated is a time series column (or bar) graph. The two graphs are of differing time resolution or differing time aggregation. 
There may be industry specific terms for these types of charts. In finance, for example, the open-high-low-close chart is a very common time series plot:

When the x axis is time, as in your example, it's often common to illustrate the points as a line graph, instead of bars/columns. The reason for this is to put the visual emphasis on the change from one period to the next. 
You might also consider graphing period-over-period. For example a year-over-year would show how the numbers for a given month (typically, although could be month or day) compare to the numbers of the prior year for the same month.

But I realize your question was about naming, not all the other cool graphs you can do ;) 
A: I'd suggest "diurnal" or "circadian" rhythm chart. For weekly, the latter would be "circaseptan", "circamensual" for "monthly", and "circannual" for "yearly".
A: The type of chart you've drawn is known as a Histogram http://en.wikipedia.org/wiki/Histogram
A: Short, simple, descriptive: time series plot. 
Edit: In light of the discussion, I'd vote for histogram as well. At least, thats the generic name for this kind of chart, where the hours of the day are a natural division of stacks.
A: Your charts are a diurnal hourly-average bar chart, and a one-week daily-average bar chart, respectively.
