Comparison

Between Dates Calendar Math vs Datum

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Between Dates Calendar Math

Calculate the number of days between two dates with a simple interface. Save, recall, sort, and remove date calculations. Add or subtract days from selected dates for quick date projections.

Highlights
  • Calculate days between dates
  • Save and recall date calculations
  • Sort and remove saved dates
  • Add or subtract days
  • Copy dates to start/end
  • Reset dates to current
Features
Read full description

Between Days was written to quickly tell how many days are between two dates. It uses a simple interface to get these answers in the quickest way possible. Underneath the simplicity, Between Days is one of the most feature rich date apps in the app store. Don’t let the simple interface fool you, this app does show a lot of information in a clean and easy to use format. To use the app simply set the start date and end date and it will display the number of days between those two dates. To select which date to edit you can either touch the date you want to change, or press the setting start date/ setting end date button. The selector will automatically change to display the date selected. It will also display the current day of the week showing on the calendar selector. If you would like to save the date for later, simply press the save button on the bottom. To recall a date, or to view saved dates press the view dates button on the bottom. Once you are at the list of dates you can sort or remove them. You can also press on a date to use it as the current date, or press done to return to your previous dates. There are also add and subtract buttons. This is useful if you need to find what the date is before or after a certain number of days, month or years. The copy to end date/copy to start date button will set both the start date and end date to the selected date. The reset button will set the beginning and end date to the current date, but will leave your saved dates alone. I hope you enjoy this app and find it useful! If you have any questions or comments send me an e-mail at Don.Espe@gmail.com Please rate this app so I know if there is enough interest to develop new features for it.

About

Datum

A minimalist calendar application designed for Apple devices, offering a clean interface and customizable widgets for iOS, macOS, and watchOS. View upcoming events, daily schedules, and monthly overviews directly from your home screen or watch face.

Highlights
  • Minimalist calendar interface
  • Lockscreen widgets for iOS
  • Event display widgets
  • Calendar widgets with event marks
  • watchOS calendar and complications
  • Support for iPhone, iPad, Mac, and Apple Watch
Features
Read full description

Datum is a minimalistic iOS, watchOS, macOS and visionOS calendar app. For iOS there are Lockscreen Widgets that show you the current date and there are Lockscreen Widgets that show up to 3 events for today. The iOS and macOS apps include the following widgets: - a small widget that shows the current date and at the bottom the events for this day - a small widget that shows a calendar with up to 3 event marks for each day - a medium widget that shows the same as the first small widget and on the right side a calendar with up to 3 event marks for each day - a large widget that shows the same as the medium widget and a list of the upcoming events - a extra large widget that shows a calendar and a list of the upcoming events (only for iPadOS 15+) The watchOS app shows a calendar with up to 3 event marks for each day. You can switch to the next/previous month by tapping on the arrows at the bottom of the calendar. You can view all events for each day by tapping on a day. There are also complications for all watchfaces included that show you the current date.

Screenshots

Between Dates Calendar Math4 screens
Datum3 screens

Verdict

The call

The clearest difference is review sentiment: Datum at 100% against Between Dates Calendar Math's 50%. Between Dates Calendar Math's advantage is price ($0.99 vs $1.99) and iOS requirement (13.0 vs 17.6). On update cadence, ads, in-app purchases and monetization model there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Between Dates Calendar Math costs $0.99 and Datum $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

Between Dates Calendar Math ships an update every 4 months, Datum every 3 months. The most recent releases landed on October 6, 2026 and October 9, 2026 respectively.

Scorecard3 real differences · 7 level
Between Dates Calendar Math versus Datum: the parameters behind the verdict, then further details
ParameterBetween Dates Calendar MathDatum
Price$0.99 — better$1.99
Rating4.8 (42 ratings) — better—
Positive reviews50.0% of reviews100.0% of reviews — better
Number of ratings42 — better—
Update frequencyEvery 4 monthsEvery 3 months — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPhone, iPad, iPod, MaciPhone, iPad, Mac, Apple Watch, Vision Pro — better
Requires iOS13.0 — better17.6
Further details — not scored
Size1 MB11 MB
Age rating4+4+
DeveloperDucky Planet LLCMichael Lindinger

Customer experience

Between Dates Calendar Math

All ratings42 ratings
Positive95.2%
Neutral0.0%
Negative4.8%
Written reviews8 reviews
Positive50.0%
Neutral25.0%
Negative25.0%

Datum

Written reviews2 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

Between Dates Calendar Math

No in-app purchases

None

Datum

No in-app purchases

Questions

Is Between Dates Calendar Math free?
Between Dates Calendar Math costs $0.99, with no in-app purchases.
Is Datum free?
Datum costs $1.99, with no in-app purchases.
Do Between Dates Calendar Math or Datum have ads?
Neither Between Dates Calendar Math nor Datum shows ads.
Which is updated more often, Between Dates Calendar Math or Datum?
Between Dates Calendar Math ships an update every 4 months, and Datum every 3 months. Most recently, Between Dates Calendar Math was updated on October 6, 2026 and Datum on October 9, 2026.

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