How To Create Filename with Date Time in Windows Batch Script

Creating files and folders with names based on the current date and time is a crucial aspect of organizing data, automating backups, and logging in Windows environments. Windows Batch Script, the scripting language for Windows Command Prompt, offers straightforward methods to incorporate date and time stamps into your filenames and directory names. This article explores how to achieve this, ensuring your scripts can dynamically generate unique and descriptive names.

Understanding Windows Batch Script Date & Time

In Windows Batch Script, the %DATE% and %TIME% environment variables provide the current date and time, respectively. However, their format is influenced by the system’s regional settings, which can vary. Typically, %DATE% returns the date in the format “Fri 03/01/2024“, and %TIME% provides the time in the format “12:30:45.78”.

Formatting Date and Time

To create file or folder names with date and time, you must extract and format these values accordingly. Since direct formatting options like in Linux’s date command are not available, you’ll often need to use substring extraction and replacement techniques.

Extracting Date Components

Here’s how you can extract year, month, and day from the %DATE% variable, assuming the format is MM/DD/YYYY:

set YEAR=%DATE:~10,4%
set MONTH=%DATE:~4,2%
set DAY=%DATE:~7,2%

Extracting Time Components

Similarly, to extract hour, minute, and second from %TIME%, you might use:

set HOUR=%TIME:~0,2%
set MINUTE=%TIME:~3,2%
set SECOND=%TIME:~6,2%

Generating Names Based on Date and Time

With the date and time components extracted, you can now combine them to form unique file or folder names.

Creating a Timestamped File Name

set FILENAME=Log_%YEAR%-%MONTH%-%DAY%_%HOUR%-%MINUTE%-%SECOND%.txt
echo Log entry > %FILENAME%

This script creates a log file named like Log_2024-03-01_12-30-45.txt.

Creating a Directory Based on the Date

For organizing backups or logs by date, you might create a directory like so:

set DIRNAME=Backup_%YEAR%-%MONTH%-%DAY%
mkdir %DIRNAME%

This command creates a directory named Backup_2024-03-01.

Handling Single-Digit Day and Month

One challenge is that single-digit months and days can lead to names with unexpected formats due to leading spaces. To ensure a consistent two-digit format, you can add a zero padding where necessary:

if %MONTH% LSS 10 set MONTH=0%MONTH:~1,1%
if %DAY% LSS 10 set DAY=0%DAY:~1,1%

A Sample Batch Script with Date & Time

To utilize the script in a Windows environment for generating timestamped filenames and directory names, follow these steps: Create a new file named script.bat and input the content outlined below. This script is designed to extract the current date and time, format these elements for consistency, and then employ them to construct a unique log file and a backup directory.

@echo off

:: Extract year, month, and day from the system's date
set YEAR=%DATE:~10,4%
set MONTH=%DATE:~4,2%
set DAY=%DATE:~7,2%

:: Ensure month and day are two digits (add leading zero if necessary)
if %MONTH% LSS 10 set MONTH=0%MONTH:~1,1%
if %DAY% LSS 10 set DAY=0%DAY:~1,1%

:: Extract hour, minute, and second from the system's time
set HOUR=%TIME:~0,2%
set MINUTE=%TIME:~3,2%
set SECOND=%TIME:~6,2%

:: Ensure hour, minute, and second are two digits (add leading zero if necessary)
if %HOUR% LSS 10 set HOUR=0%HOUR:~1,1%
if %MINUTE% LSS 10 set MINUTE=0%MINUTE:~1,1%
if %SECOND% LSS 10 set SECOND=0%SECOND:~1,1%

:: Create a log file with the current timestamp in its name
set FILENAME=Log_%YEAR%-%MONTH%-%DAY%_%HOUR%-%MINUTE%-%SECOND%.txt
echo Log entry > %FILENAME%

:: Create a directory with the current timestamp in its name
set DIRNAME=Backup_%YEAR%-%MONTH%-%DAY%
mkdir %DIRNAME%

After saving the script as script.bat, you can run it by double-clicking the file or executing it from the command prompt.

You will find that a directory is created with the name “Backup_2024-03-02”. Also, a file created in the current directory with the name “Log_2024-03-02_07-02-07.txt” (Filename will be according to current date and time and will change during your testing)

Conclusion

Generating file and folder names based on the current date and time in Windows Batch Script requires a bit more manual effort compared to other scripting environments. However, by extracting and formatting date and time components, you can create meaningful, unique names for files and directories. This approach is invaluable for automated data management tasks, ensuring your scripts can handle files in an organized, chronological manner.