The present invention features an electronic calendar device. The device includes a touch screen, a mounting mechanism, a battery component, a memory and a microprocessor. The microprocessor causes the touch screen to display a default monthly calendar window on the screen, wherein the window takes the space of screen displaying the current month and a table comprising weekdays and dates. The user can select the desired date for event input. When the current date has an event, the microprocessor causes the default window automatically to shrink to the smaller window occupying the first half of the screen, and the event window pops up to occupy the remaining half of the screen and display the event content.