Parsley hates the heat. Not a summer plant. Every plant in that pot will be stressed from a cycle of too much water at one point in the day and then drying out by the end of the day. Stressed plants drop their oldest leaves first. Repot them in a much larger pot with proper drainage!and cut the basil back by half.

In addition to what reba said: make sure the soil you use has some water-holding crystals in it... you can buy potting soil with it already in it, or you can buy a jar of the crystals and add some to the soil yourself; this will help while you're gone during the day. Also, use a plastic pot instead of a terra cotta one, it won't dry out as fast; if it gets really hot up there you could use a pot-within-a -pot to help keep the roots cooler.... a smaller pot inside a bigger pot with some moss or even soil in-between. You might want to put up some sort of shade barrier so these herbs don't get the hot afternoon sun. But, keeping the soil dampish all the time is the most important.

I have all of my herbs in pots...but they have drainage holes. If you're using the water crystals, you shouldn't be watering them every day unless its a 100 degrees outside and they're showing a little drooping. HTH.