second

Seconds component of input date and time

Syntax

s = second(t)

s = second(t,secondType)

Description

s = second(t) returns the seconds component for each date and time specified in t. The seconds component of a date and time can include a fractional part.

The s output is a double array and contains values from 0 to less than 60. To assign values to the seconds components of values in t, use t.Second and modify the Second property.

s = second(t,secondType) returns the type of seconds of datetime array t, specified as either "secondofminute" or "secondofday".

Examples

Find Second Number of Datetime Values

t1 = datetime('now','Format','dd-MMM-yyyy HH:mm:ss.SSS');
t = t1 + seconds(30:15:60)

t = 1×3 datetime
   09-Aug-2025 12:20:06.021   09-Aug-2025 12:20:21.021   09-Aug-2025 12:20:36.021

s = second(t)

s = 1×3

    6.0218   21.0218   36.0218

Input Arguments

t — Input date and time

datetime array

Input date and time, specified as a datetime array.

If the time zone of t is UTCLeapSeconds, then s can contain a value between 60 and 61 for any time that falls during a leap second occurrence.

To support existing code that previously required Financial Toolbox™, second also accepts serial date numbers and text as inputs, but they are not recommended. For more information, see Version History.

secondType — Type of second values

'secondofminute' (default) | 'secondofday'

Type of second values, specified as either 'secondofminute' or 'secondofday'.

• If secondType is 'secondofminute', then second returns the second of the minute.

• If secondType is 'secondofday', then second returns the second of the day, which (except for leap seconds) is in the range [0, 86400).

This argument is valid only when t is a datetime array.

Extended Capabilities

Tall Arrays

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

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

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

R2022a: Serial date number and text inputs not recommended

Although second supports serial date number and text inputs, datetime values are recommended instead. The datetime data type provides flexible date and time formats, storage out to nanosecond precision, and properties to account for time zones and daylight saving time.

To convert serial date numbers or text to datetime values, use the datetime function. For example:

t = datetime(738427.656845093,"ConvertFrom","datenum");
s = second(t)

s =

   51.4160

There are no plans to remove support for serial date number or text inputs.

R2022a: second functions from Financial Toolbox and MATLAB combined

In previous releases, there were two second functions: one in MATLAB^® that accepted datetime values, and one in Financial Toolbox that accepted serial date numbers or text values. As of R2022a, you can call second without Financial Toolbox. When you call second from MATLAB, it accepts all previous input types.

For example, you can make these calls with a serial date number and text from MATLAB:

s = second(738427.656845093)

s =

   51.4160

s = second("2021/09/28 15:45:51.4160")

s =

   51.4160

In addition, second accepts a second input for the date format when the first input is not a datetime array:

s = second(t,F)

In this syntax, specify F using a valid date format as documented for the datestr function, though 'Q' format specifiers are not supported. For example:

s = second("2021/09/28 15:45:51.4160","yyyy/dd/mm hh:MM:ss.fff")

s =

   51.4160