--- title: Jet Lag App Entrain by University of Michigan description: App to help travelers get over jet lag more quickly developed by mathematicians at the University of Michigan canonical: https://time.com/59543/this-app-is-supposed-to-help-you-get-over-jet-lag/ author: Olivia B. Waxman article:opinion: false article:content_tier: free article:published_time: 2014-04-11T17:08:12.000Z article:modified_time: 2026-04-13T07:08:44.025Z og:title: This App Can Help You Quickly Recover From Jet Lag og:description: Developed by math researchers at the University of Michigan, it claims to cut down jet lag at either end of a trip by about half og:url: https://time.com/59543/this-app-is-supposed-to-help-you-get-over-jet-lag/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/bltde093bcdab65f2d0/6988d9b9bc6cfc69913e2a3c/time-logo.jpg?branch=production og:image:width: 1200 og:image:height: 675 og:image:alt: TIME og:type: article twitter:card: summary_large_image twitter:title: This App Can Help You Quickly Recover From Jet Lag twitter:description: Developed by math researchers at the University of Michigan, it claims to cut down jet lag at either end of a trip by about half twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/bltde093bcdab65f2d0/6988d9b9bc6cfc69913e2a3c/time-logo.jpg?branch=production --- # This App Is Supposed to Help You Get Over Jet Lag  by [Olivia B. Waxman](https://time.com/author/olivia-b-waxman/)  ## Olivia B. Waxman Staff Writer Apr 11, 2014 5:08 PM UTC  by [Olivia B. Waxman](https://time.com/author/olivia-b-waxman/)  ## Olivia B. Waxman Staff Writer Apr 11, 2014 5:08 PM UTC NPR Health blog [“Shots”](http://www.npr.org/blogs/health/2014/04/11/301579620/this-jet-lag-app-does-the-math-so-youll-feel-better-faster) and [Quartz](http://qz.com/196913/you-can-now-reprogram-your-sleep-patterns-with-your-iphone-when-you-travel/) have profiled an app that is supposed to help globetrotters recover from jet lag more easily. Users select the timezone they’re flying into, and the iOS program, which is called [Entrain](http://entrain.math.lsa.umich.edu/?%5Fga=1.114844932.2068559080.1374864028), illustrates in a flow graphic when to stay in bright or low light and when to be in dark light throughout their trip, based on the kinds of mathematical equations that NASA and the military use to anticipate how light affects the human circadian clock. For example, people who fly from New York to Tokyo could feel jet-lagged for as many as 12 days, and this app hopes to radically reduce recovery time to 3-5 days altogether, Quartz [reports](http://qz.com/196913/you-can-now-reprogram-your-sleep-patterns-with-your-iphone-when-you-travel/). To create the app, NPR [explains](http://www.npr.org/blogs/health/2014/04/11/301579620/this-jet-lag-app-does-the-math-so-youll-feel-better-faster) that the developers, a University of Michigan graduate student Olivia Walch and professor of mathematics and computational medicine Danny Forger, --- > “” --- The app has not been flight-tested yet, but Forger and his colleagues published a study in [PLOS Computational Biology](http://www.ploscompbiol.org/article/info%3Adoi%2F10.1371%2Fjournal.pcbi.1003523) Thursday with research that is supposed to back up Entrain’s methodology. ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/59543/this-app-is-supposed-to-help-you-get-over-jet-lag/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/59543/this-app-is-supposed-to-help-you-get-over-jet-lag/"},"headline":"This App Is Supposed to Help You Get Over Jet Lag","datePublished":"2014-04-11T17:08:12.000Z","dateModified":"2026-04-13T07:08:44.025Z","description":"Developed by math researchers at the University of Michigan, it claims to cut down jet lag at either end of a trip by about half","url":"https://time.com/59543/this-app-is-supposed-to-help-you-get-over-jet-lag/","keywords":["Newsfeed","Technology"],"thumbnailUrl":"","author":[{"@type":"Person","name":"Olivia B. Waxman","jobTitle":"Staff Writer","url":"https://time.com/author/olivia-b-waxman/"}],"articleSection":"","image":[],"publisher":{"@type":"Organization","name":"Time","url":"https://time.com/","logo":{"@type":"ImageObject","url":"https://time.com/images/logo.png","width":528,"height":156},"foundingDate":"March 3, 1923","sameAs":["https://www.facebook.com/time","https://www.instagram.com/time/?hl=en","https://twitter.com/time","https://www.pinterest.com/timemagazine"]}},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/tag/time-section-newsfeed/","name":"Newsfeed"}},{"@type":"ListItem","position":2,"item":{"@id":"https://time.com/59543/this-app-is-supposed-to-help-you-get-over-jet-lag/","name":"This App Is Supposed to Help You Get Over Jet Lag"}}]}] ```