•Arnošt Havelka
Variables and Time
Use environment variables and time commands to build predictable automation and timestamped logs.
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Variables and Time
Variables and timestamps are the backbone of maintainable batch workflows. Without them, scripts hardcode paths, logs become inconsistent, and debugging gets painful.
Core Idea
Use variables for values that change between machines or runs, and use time values to stamp outputs so every run is traceable.
Usage:set
LOG_DIR
=C:\\Logs
&& echo %DATE% %TIME%set NAME=value
Create/update variable for current shell session.
%NAME%
Resolve the variable value in commands.
%DATE% %TIME%
Emit execution timestamp for logs and reports.
Step 1: Read Existing Environment Values
Command Prompt
C:\Users\User>echo %PATH%
This confirms what executables your session can find without full paths.
Step 2: Build a Timestamped Log Entry
Command Prompt
C:\Users\User>echo Backup started at %DATE% %TIME% >> backup.log
Appending date/time entries makes audits and rollback investigations much faster.
Reliable Pattern
- Use
setfor dynamic directories and environment-specific values. - Use
%DATE%and%TIME%in every operational log line. - Avoid hardcoded paths when scripts will run on multiple machines.
This single pattern greatly improves script portability and incident traceability.
References
These Microsoft Learn and Windows documentation links provide authoritative details for the commands used in this article.