Time

What it does

Some layers depend on time: where night falls, where the sun and moon stand, and which latitudes get twelve hours of daylight. The time slider lets those layers show another moment instead of only now.

The main switch is Now:

• on: the map uses the current time.
• off: the map uses the time set by the sliders.

Time of day and date are separate sliders. The year picker reaches far enough for cycles that do not fit in one year, such as the moon's 18.6-year north-south swing.

Press play to advance the slider.

Using it

1. Turn Now off to take control of the moment.
2. Move the time-of-day slider to watch the terminator sweep round. Move the date to watch the seasons change where it falls.
3. Play to run it. Turn Now back on to return to live.

In your own map

Add timeSlider to a toolbar, and give the map at least one layer that depends on the clock. The computed day/night, sun, and moon layers all do.

The clock lives in the map's store as mapTime, not in the panel. A chosen moment survives closing the tool, and two maps on one page can use different moments.

Extending it

The spinner deliberately hides while the clock is playing: an animation never reaches idle, so a busy indicator would latch on for the whole run and read as a map stuck loading rather than a map running.