30 Minute Timer

About the 30 minute timer

Half an hour is the length of a task that deserves a slot rather than a note. A focused stretch of work. A run. A dough proving. Most of the world's meetings, most of the world's television, and the point at which a parked car, a laundry cycle or a parking meter starts to matter.

It is also long enough that people stop watching it, which is the whole design problem with a thirty minute timer and the reason this one is built the way it is. The remaining time is worked out from a deadline on the system clock, so a tab left in the background, a browser throttling its timers to save battery, or a laptop that slept and woke all arrive at the same answer. The alert fires when it should, whether or not this is the tab you are looking at.

The tab title carries the remaining time, so a row of tabs tells you where the timer is without clicking into it. The screen is kept awake while it runs so a propped up phone does not go dark.

Press start and the ring drains once around over the half hour. Three rising notes at the end, silenceable with the speaker button if the room needs it.

For half an hour split into work and rest, use the interval timer, which sounds the last three seconds of each phase so you do not have to watch the screen at all.

Half an hour is the shape of most public health advice about movement. The widely quoted guidance of 150 minutes of moderate activity a week is usually translated as thirty minutes on five days, and the translation matters more than the total: thirty minutes is a length people can find, whereas 150 minutes a week is a number nobody acts on. Splitting it into three lots of ten counts just as well, which is worth knowing on a day when thirty is not available.

In cooking, half an hour is the low attention interval. It is roughly how long a tray of vegetables wants at a high oven temperature before it needs turning, how long most doughs want before a first look, and how long a stock wants before it is worth tasting. In all of those the value of a timer is not precision but permission: you can leave the kitchen entirely, which you cannot do while keeping half an eye on the oven.

Half an hour is the shape of most public health advice about movement. The widely quoted guidance of 150 minutes of moderate activity a week is usually translated as thirty minutes on five days, and the translation matters more than the total: thirty minutes is a length people can find, whereas 150 minutes a week is a number nobody acts on. Splitting it into three lots of ten counts just as well, which is worth knowing on a day when thirty is not available.

In cooking, half an hour is the low attention interval. It is roughly how long a tray of vegetables wants at a high oven temperature before it needs turning, how long most doughs want before a first look, and how long a stock wants before it is worth tasting. In all of those the value of a timer is not precision but permission: you can leave the kitchen entirely, which you cannot do while keeping half an eye on the oven.

Other lengths

• 1 Minute Timer
• 3 Minute Timer
• 5 Minute Timer
• 10 Minute Timer
• 15 Minute Timer
• 20 Minute Timer
• 1 Hour Timer