What kind of grass do you have?

If you aren't sure, see below.

Here is a link that might be useful: Grass ID

It looks like KBG. Not 100% sure though. The report said cool season turfgrass. Additionally I plan on dethaching and aerating/overseeding in the fall.

Caveat: The following are supported by at least some type of study (or possibly an informed opinion) by a university turf program or turf organization.

Common to all cool season grasses:
Root growth is at its maximum when soil temperatures are between 50 and 65F. (spring and fall)
They exhibit a spring flush.
Top growth slows/stops and they tend to go dormant in the heat of summer and when drought conditions are present.
Top-growth slows significantly or stops in the fall. They can go dormant over the winter.
They exhibit a tendency to store carbohydrates at various times for survival. (early summer to allow recover after drought dormancy and in late fall for recover after winter dormancy)
Spring fertilization has been tied to increased susceptibility to disease.

Specific to rhizome grasses -KB:
They exhibit greater root growth during the fall/winter than during spring/summer.
They exhibit greater spreading ability in the spring than in the fall.

Fertilization programs are or should be designed to fit those characteristics.
A late fall fertilization ( applied after top growth has significantly slowed or stopped--called winterizing) is pretty universally advised for all cool season grasses to promote root growth, carbohydrate storage and early spring green-up.
A mid-late fall fertilization is optional but advised when needed to stimulate the turf and promote continued photosynthesis so the turf can efficiently use the winterizing application. This application should be avoided if it promotes continued top growth -suspected in the increased incidence of snow mold.
A late summer fertilization is advised for all cool season grasses to help the the turf recover from summer dormancy and stress. It is applied after the turf begins to green up and top growth resumes.
A late spring/early summer fertilization is advised for all cool season grasses to promote turf health, continued growth and carbohydrate storage to prepare the turf for the heat of summer. It should be applied once the spring flush dissipates.
An early spring fertilization is sometimes recommended when a winterizing was not done the prior year. It can also be applied to rhizome grasses-KB to promote spreading when there are bare or thin areas throughout the lawn but should be avoided when those lawns are healthy and thick. The use of this application needs to be balanced with the increased chance of disease. It is advised that it never be applied to fescue lawns due to disease susceptibility. (It is also suspected that this application promotes top growth at the expense of root growth).

The best schedule is one based on observation.

Hope that helps you develop your program and schedule.

This post was edited by yardtractor1 on Tue, Jun 3, 14 at 14:42

Thanks! Do you have an opinion on something like milorganite for the summer application?

A number of years ago I used Milorganite and some other organic products regularly from May through September to maintain a base line which I then suplimented with synthetics to promote desired turf characteristics (see prior post). The WSN in Milorganite at the time was quite low but has since been increased significantly. Once I went to a fixed income, I only use Milorganite once a year primarily for the iron and OM.
My only issue with organic fertilizers, as a sole source, is they are environment dependent and I know of no way of calculating or controlling the timing or amount of nutrient availability. I have no reason to advise against it, but I know there are others here who have more recent and prolific experience with Milorganite and other organic products and would defer to them.