International Lolita Day (often shortened to ILD) is a day set aside for meet-ups around to world and is hosted bi-annually every year - once on the first Saturday of June and then the first Saturday of December - both to allow lolita's of all styles to dress up in both their Summer wear and also their Winter wear.
Lolita meet-up

A group of Lolitas in the general LA area

Lolita day was first coined on the EGL Community on liveJournal, but has since become known rather worldwide and many loli's gather in major cities.

Meet-ups are often hosted on other days of the year, and there is no one person making "official" ILD meet-ups, they are simply decided upon within local communities.

Lolitas who do not have an active local group will often set aside this day to get dressed up anyways and will sometimes plan something special to do by themselves.