# Julianator — Julian Day of Year Calculator > Converts dates between Gregorian and Julian Day of Year (ordinal date). (iPhone/iPad app by Bright Day Digital LLC.) - Source: https://appshunter.io/ios/app/julianator/id383950353 (this page in markdown: same URL + `.md`) - Developer: [Bright Day Digital LLC](https://appshunter.io/developer/383950356) - Category: Utilities, Reference - Price: $0.99 (on sale, was $1.99) - Rating: 4.70/5 from 111 App Store ratings · 27 written reviews indexed - Age rating: 4+ - Requires: iOS 17.4 · 4 MB - Languages: American English - Released: 2010-07-30 - Data updated: 2026-09-01 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/julianator/id383950353/reviews.md ## What is Julianator? This app converts a date between Julian Day of Year and Gregorian. For example, September 11, 2022 converts to 2022-254 and 2022-254 converts to September 11, 2022. This app will convert both directions. Julian Date for this app refers to the day-of-year number (more properly, the ordinal date) in the Gregorian calendar, often used in mainframe computer systems, the military, and the food industry. (Note: this app does not used the term Julian Date to refer to the astronomy definition which is calculated from 4713 BC) Features a simple clean interface with pickers for the dates. The app also features a monthly view allowing a quick view of both Gregorian and Julian days for the entire month. Widgets are available for both the Home Screen and the Lock Screen to display the current day of year. A Watch app is available that includes a date converter and complications to display the current day of year. Note: The app's icon does not change to reflect the current day. Privacy Policy: https://julianator.brightdaydigital.com/privacy Terms of Service: https://julianator.brightdaydigital.com/terms ## Key features - Gregorian to Julian Day of Year conversion - Julian Day of Year to Gregorian conversion - Monthly calendar view - Home Screen widgets - Lock Screen widgets - Watch app with complications ## Chart rankings - #116 in Top Paid · Utilities (US App Store) ## Recent user reviews (10 of 27) All indexed reviews: https://appshunter.io/ios/app/julianator/id383950353/reviews.md ### 4/5 — Still does not handle leap years *2026-06-17, version 4.7* This app still does not handle Dec. 31 at the end of leap years. ### 2/5 — Widget doesn’t work *2024-10-23, version 4.4* The lock screen widget doesn’t work. The current Julian date should display in the icon without having to open app. ### 1/5 — Fix widget *2024-09-18, version 4.3* Is there a way to fix the widget. I want the see the actual Julian date with out clicking the widget. The widget displays “2024-2..” ### 1/5 — No complications *2023-01-23, version 4.0* Does not show in the list of available complications. That’s what I wanted for. ### 5/5 — Awesome! *2022-10-28, version 4.0* I’m retired military, and work for the government as a civil servant. I use the Julian date daily, as many in the government do. I love this app! The fact that it has a watch complication and a iPhone widget, makes it absolutely perfect in my opinion. ### 5/5 — The best *2022-09-24, version 4.0* Amazing app, appreciate its simplicity. Use it in the aerospace industry all the time. Thanks to the developer for keeping it going all these years! ### 5/5 — ). This is the app on iOS *2021-12-15* This is the app you are after if you are in the food related industry. After trying others and having nightmares with apps not updating daily and giving me astronomical conversions ( both paid and free ). This is the app on iOS ### 4/5 — Needs to Display Date on Icon *2021-03-02, version 3.0.0* This app would get five stars if it displayed the Julian date on the app’s homescreen icon. ### 5/5 — Perfect for work *2019-06-08, version 3.0.0* I deal with Julian dates all the time at work and this is the perfect app for it. You can search by Julian date or search by regular date and it just makes life simple. Thank you. ### 5/5 — Perfect!! *2019-06-08, version 3.0.0* Simple, quick, and exactly what I needed to project and plan events a certain amount of days out within the year. No frills I don’t need, no nag screens or ads, and with perfect displays. A big thanks the creator(s). ## Frequently asked questions about Julianator ### What does the Julianator app do? The Julianator app converts dates between the standard Gregorian calendar and the Julian Day of Year, also known as the ordinal date. This is useful for systems that track days sequentially within a year, often used in mainframe computing, military operations, and the food industry. ### What are the key features of Julianator? Key features include bidirectional date conversion (Gregorian to Julian Day of Year and vice versa), a clean interface with date pickers, a monthly view showing both calendar systems, and widgets for both the Home Screen and Lock Screen to display the current day of year. A companion Watch app is also available. ### Is Julianator free to use? Yes, the Julianator app is free to download and use. The provided information indicates it does not have ads or in-app purchases, suggesting a completely free experience for users. ### What devices is Julianator compatible with? The app is available for mobile devices, with specific mention of a Watch app for Apple Watch. Widgets are also available for both the Home Screen and Lock Screen, indicating compatibility with modern smartphone operating systems that support these features. ### What is the difference between Julian Day of Year and the astronomical Julian Date? This app specifically refers to the Julian Day of Year as the day-of-year number within the Gregorian calendar, also known as the ordinal date. It explicitly states that it does not use the astronomical definition of Julian Date, which is a count of days from a specific epoch in 4713 BC. ## Version history (last 5 releases) ### 4.7 — 2025-09-18 Support for iOS 26 Liquid Glass ### 4.6 — 2025-08-04 Added anonymous analytics for better user support Allow app to occasionally request reviews Updated Privacy Policy: https://julianator.brightdaydigital.com/privacy Added Terms of Service: https://julianator.brightdaydigital.com/terms ### 4.5 — 2024-12-08 Update to fix widgets with issues on some devices. ### 4.4 — 2024-09-18 Fix text sizing issue for widget. ### 4.3 — 2024-09-16 This update adds a dark mode icon. 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User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-01.*