days

Duration in days

Syntax

D = days(X)

Description

D = days(X) returns an array of fixed-length days equivalent to the values in the input array.

• If X is a numeric array, then D is a duration array in units of fixed-length days. A fixed-length day is equal to 24 hours.

• If X is a duration array, then D is a double array with each element equal to the number of fixed-length (24-hour) days in the corresponding element of X.

The days function converts between duration and double values. To display a duration in units of days, set its Format property to 'd'.

Examples

Create Duration Array of Fixed-Length Days

X = magic(2);
D = days(X)

D = 2×2 duration
    1 day   3 days
   4 days   2 days

Add each number of fixed-length days to the current date and time.

t = datetime('now') + D

t = 2×2 datetime
   10-Aug-2025 12:03:36   12-Aug-2025 12:03:36
   13-Aug-2025 12:03:36   11-Aug-2025 12:03:36

Convert Durations to Numeric Array of Days

Create a duration array.

X = hours(23:20:95) + minutes(45)

X = 1×4 duration
   23.75 hr   43.75 hr   63.75 hr   83.75 hr

Convert each duration in X to a number of days.

D = days(X)

D = 1×4

    0.9896    1.8229    2.6562    3.4896

Input Arguments

X — Input array

numeric array | duration array | logical array

Input array, specified as a numeric array, duration array, or logical array.

Tips

• days creates fixed-length (24 hour) days. To create days that account for Daylight Saving Time shifts when used in calendar calculations, use the caldays function.

Extended Capabilities

Tall Arrays

Calculate with arrays that have more rows than fit in memory.

The days function fully supports tall arrays. For more information, see Tall Arrays.

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

This function fully supports code generation. For more information, see Code Generation for Duration Arrays (MATLAB Coder).

Thread-Based Environment

Run code in the background using MATLAB® backgroundPool or accelerate code with Parallel Computing Toolbox™ ThreadPool.

This function fully supports thread-based environments. For more information, see Run MATLAB Functions in Thread-Based Environment.

Distributed Arrays

Partition large arrays across the combined memory of your cluster using Parallel Computing Toolbox™.

This function fully supports distributed arrays. For more information, see Run MATLAB Functions with Distributed Arrays (Parallel Computing Toolbox).

Version History

Introduced in R2014b