Date From A Year Ago
Here’s a handy little script that has multiple applications to calculate date from a year ago.
<pre lang="bash">
#!/bin/bash
now=$(date +%Y%m%d-%H%M%S)
# mac os
year_old=$(date -v-1y +%Y%m%d-%H%M%S)
# linux os
year_old=$(date -d "-1 year" +%Y%m%d-%H%M%S)
echo $now
echo $year_old
Mac Os and Linux has slightly different formats. Pick one based on your OS.
Results
<pre lang="bash">
20230618-084940
20220618-084940