Calculate time 4 hours earlier in bash

time_calc.sh

#!/bin/bash

# Get the current time in UTC
CURRENT_TIME=$(date -u +'%FT%T')
EARLIER=$(date -u -d '-1 hour' +'%FT%T')

echo "Current Time: $CURRENT_TIME"
echo "One Hour Earlier: $EARLIER"

# Calculate four hours earlier
FOUR_HOURS_EARLIER=$(date -u -d '-4 hours' +'%FT%T')

echo "CURRENT_TIME: $CURRENT_TIME"
echo "ONE_HOUR_EARLIER: $EARLIER"
echo "FOUR_HOURS_EARLIER: $FOUR_HOURS_EARLIER"