If you're going to build a project that consumes very little current, the last thing you need is a display that chews all your power.

This LCD display is designed to run at 3V up to 5V, and consumes merely 20uA at 3V.  And just to make it easy, it is addressable using a syncronous serial connection (clock and data), so with two pins your microcontroller can be telling the time, displaying the temperature, or anything else you need to show.

It has nice, big 30mm digits and a wide angle of view, however it does have a backlight if you want to make the display visible at night time.  Each digit has a period / full stop, and a colon is a available between the two middle digits.