Midsummer, also known as Litha is celebrated June 21st. I know that I am a little late for this but, tonight is Moon Garden Grove's ritual for the midsummer festivities. I am looking forward doing the ritual and doing the BBQ afterwards with my group.
Some history on Midsummer:
The time of year it is approximately June 21 [December 21 if you are on the other side of the equinox]. The holy day is connected with nature spirits such as Elves and Fairies. The Vikings called this holy day Sonnenwende, or Sun's Turning, because it is the balance of light and dark. When day and night is equal to each other.
You can find an awesome article with more in depth history of Midsummer on PaganPages.org it also has great correspondences to look up and see if you are in need of ideas for food, incense, or some of the purposes behind celebrating this holy day.
I hope you enjoyed this day as much as I did!