A lot depends upon your soil (porosity,humus content etc.). Your burr oaks (and most of the other trees we plant in the USA) are not adapted to daily drenchings since we have very little rainforest (a small section of the Pacific Northwest excepted). A good rule is to mimic ideal natural conditions. Soak the soil around your trees then allow several days for the soil to dry out (not to a total absence of moisture) then rewet.I generally advise watering new plantings twice per week for a couple/ few weeks following planting ,then one soaking per week. A good rule of thumb that John Sanborn recommends is 1" of water per week. That 1" needs to mimic an inch of precipitation over the area, so if you are simply filling a small well around the tree you will need more than an inch over the 3 or 4 square feet inside the well.
Remember to mulch to conserve the water you add. At the height of a drought you can add 10 gallons a week to a 1-2 inch caliper tree.
Best to take a 5 gallon bucket and drill a small <1/8 inch hole on the side at the base and stand it next to your tree. This will slow water your tree and you will know how much you've watered.