Time Controls: Scrub the Sky Forward and Backward

Most planetarium apps show you right now and stop there. Ours has a whole section of its control rail devoted to a single question: what moment, exactly, are you looking at? Once you know where that section lives and what each piece does, you can put any night in history — or any night yet to come — directly overhead.

Open the rail and find the When section

The control rail lives behind a toggle button that reads "Sky controls" when closed and "Hide controls" when open; on screens wider than 900 pixels it starts open automatically. Inside, the time controls sit in a section labeled "When," separate from the location fields below it and the layer toggles below that. The current simulated moment itself — the actual clock readout with date, weekday, and time, plus your observer's coordinates — isn't inside this panel at all. It's pinned to the bottom-left corner of the sky itself, so you can always see what moment you're looking at without opening anything.

The three jump shortcuts

Three buttons sit at the top of the When section, and each one moves the simulated clock to a specific moment instantly.

Tonight jumps straight to the real current moment and starts the clock playing again at real-time speed. My birth sky jumps to whatever birth date and time you've saved and pauses there, holding that exact sky still so you can study it. Next birthday jumps forward to the next calendar occurrence of your saved birth month and day — not your literal birthday hour, just the date — and pauses there too. Both of the birthday-related buttons stay disabled until you've actually entered a birth date; there's no way to trigger them on an empty chart.

The two date fields, and the timezone rule that governs both

Below the three shortcuts sit two separate datetime fields. Birth date and time is where you record your own birth moment — this is what feeds My birth sky, Next birthday, and the "Your transits" section of the sky chart panel. Jump to a moment is a free time-machine field: type in literally any date and time, past or future, and the whole sky recomputes to match it, planets, constellations, and all.

Both fields carry one small printed rule directly underneath them: both times use this device's timezone. That's worth sitting with for a second. If you type in a moment from a trip to another timezone, or a historical event reported in a different zone than the one your device is currently set to, the sky map will read your input as local-to-you time, not local-to-the-event time — you have to do that conversion yourself before typing it in. There is no timezone picker anywhere in this field.

Play, Pause, and four named speeds

Beneath the date fields is a row that starts the clock actually moving: a single Play or Pause toggle, followed by four speed buttons. They are labeled Live, 1 min per second, 1 hour per second, and 1 day per second, corresponding to the sky advancing at real time, sixty times real time, thirty-six hundred times real time, and just over eighty-six thousand times real time. Pick 1 day per second and watch a full month of Moon phases cycle past in about thirty seconds; drop back to Live and the sky settles into moving at the same pace the actual night outside you is moving.

Whatever speed you're on keeps running until you change it or hit Pause — jumping to a new moment with any of the shortcuts or the date fields doesn't reset your chosen speed, it just relocates the clock and keeps going from there. That makes it easy to, say, jump to a specific historical night and then let 1 hour per second carry you forward from it to see what the sky did next.

What time controls do not touch

It's worth knowing what stays untouched by anything in this section. The observer's location — your latitude and longitude — lives in its own separate part of the rail below the time controls, and moving through time here never changes where you're standing; see setting your location, and why it changes everything for that half of the picture. And the Sky chart panel, which reads whatever moment the time controls are currently set to, updates its placements table live as you scrub — there's no separate refresh step. For a full tour of that panel once you've landed on a moment worth studying, reading your sky chart covers every section of it.

If you've never opened the control rail at all, how to use the Real Sky map is the place to start before diving into any one section, including this one, in depth.

What this means for you tonight

Open the rail, tap Jump to a moment, and type in the exact date and time you were born instead of using My birth sky — then compare what the sky chart shows against what My birth sky gives you once you've saved that date properly. They should match exactly, and confirming that they do is the fastest way to trust every other reading this page gives you afterward. If they don't match, the difference is almost always a timezone slip, since both fields silently assume your device's current timezone rather than wherever you actually were the day you were born.