What kind of chart?

I have a chart of times vs dates, where an event can occur
many times during a day.

for example, my table is written thus:
Mon Tue Wed Thu
0700 0730 0700 0800
0730 0800 0830
0900

I would like the chart to appear something like this:

0900 X
X
0800 X X
X X
0700 X X
Mon Tue Wed Thu

In the table, I don't want a different line for each time,
because they are actually a minute apart, and are
copy&pasted from another app.

In the chart I would like to have some marker (a dot) at
the time where it occurred, and one day's woth of times
should stack directly on top of each other.

I have had a play with various chart types, but I can't see
one that fits my needs.

Any help?

Cheers!
Wendy.