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Day One: Daylight

April 6th, 2009

[Update 04/08/2009 – Daylight is available on the App Store. Have a look, it’s free!]
[Update 19/07/2009 - Daylight has been submitted to the App Store!]
[Update 19/07/2009 - Twilight is now called Daylight.]

Six Days of Cocoa: Day One

I found myself with six unexpected days off, so I decided to take them on six consecutive Mondays, when the kids are in school and most of the housework is done, to concentrate on my independent Cocoa projects. These are projects that I started but put on the back burner for lack of “quality time”.

Day One: Daylight

Daylight is an iPhone application that I wrote to scratch an itch: when does the sun rise or set every day? It’s important to me because I bike to work year-round, and cars can see me much better at dusk than they can at night.

It’s also useful for photographers and filmmakers. One hour before sunset is the so-called “golden hour“, where the shadows are long and the scenery is tinted with an amber glow. Dusk and dawn also form the “blue hour“, much more important at higher latitudes, where there is no direct sunlight; everything is diffused through the atmosphere. No shadows, no glare, no overexposure…

Daylight is extremely simple. It uses Core Location to determine where you are in the world, and uses the internal clock to figure the current time, and offset from GMT.

There are only a few settings in Daylight . You can choose between Civil, Nautical and Astronomical twilight, set the date (defaults to Today) and reset your location (which is cached for 30 days by default).

Daylight is perhaps the very definition of a one-shot app: you launch it, it does what it says, and you’re done. It encourages discoverability by having large buttons and a little bit of animation.


Today, I found the one bug that was preventing me from going forward, so I am looking for beta-testers for Daylight . If you are interested, please send me a direct message on Twitter (d daylightapp) or send an email to daylight-beta@casgrain.com with your device’s identifier.

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  1. April 6th, 2009 at 15:19 | #1

    Looks great, Phil, and useful too.

  2. Henry
    September 2nd, 2009 at 06:40 | #2

    Just wanted to say how much Iove this app. I looked at a few of the paid sunrise apps but they all looked way too gimmicky to be worth anything.

    As you said Daylight is a definitive iPhone app; It does one thing, does it very well, and never looses sight of it’s goal. Great work!

  3. September 2nd, 2009 at 07:59 | #3

    @Henry
    Thanks Henry!

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