Date Command Issue in Linux vs macOS/BSD Environments

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Problem Description

The dspm-data-generator.sh script contained BSD-style date commands that are incompatible with GNU date (used in Linux environments like AWS CloudShell). This caused the script to fail when executed in Linux-based environments.

Root Cause

The script uses BSD date syntax with the -v flag:

date -v-"$((RANDOM % 365))d" +%Y-%m-%d

Why this fails in Linux:

• The -v flag is specific to BSD date (commonly found on macOS)
• GNU date (used in most Linux distributions, including AWS CloudShell) doesn't recognize the -v flag
• This results in "invalid option" or "command not found" errors

Technical Details

• BSD date syntax: date -v-30d (subtract 30 days)
• GNU date syntax: date -d "30 days ago" (subtract 30 days)

The two implementations have completely different approaches to date arithmetic.

Solution

Replace all instances of BSD-style date commands with GNU-compatible equivalents:

Before (BSD/macOS):

date -v-"$((RANDOM % 365))d" +%Y-%m-%d
date -v-"$((RANDOM % 30))d" +%Y-%m-%d

After (GNU/Linux):

date -d "$((RANDOM % 365)) days ago" +%Y-%m-%d
date -d "$((RANDOM % 30)) days ago" +%Y-%m-%d

Environment Compatibility

• Works on: macOS, FreeBSD, OpenBSD (BSD date)
• Fails on: Linux distributions, AWS CloudShell, most CI/CD environments (GNU date)
• Target fix: Make script compatible with GNU date for broader Linux support

Verification

To test which date implementation you're using:

# BSD date will work:
date -v-1d 2>/dev/null && echo "BSD date" || echo "GNU date"

# GNU date will work:
date -d "1 day ago" 2>/dev/null && echo "GNU date" || echo "BSD date"

This type of issue is common when scripts are developed on macOS and then deployed to Linux environments, as the default date implementations differ significantly between the two platforms.