FreeBSD/vrac/SixM.sh

#!/bin/sh

# Six month ago
# -------------

SIXM=`date -j -v"-6m" +"%F %T"`

## Epoc 
SIXM_EPOC=`date -j -f "%F %T" "$SIXM" "+%s"`

## express SQL date into epoc time
## 

SQL_DATE_EPOC=`date -j -f "%F %T" "${1}" "+%s"`

##  test sql_date < sixm

[ "${SQL_DATE_EPOC}" -gt "$SIXM_EPOC" ] && echo "match"