#current date for GMT+8 (i.e.: SGT, BJT)

TZ=xx-8 date

#current date time – 15 mins back

TZ=xx-7:45 date

#current date time + 15 mins back

TZ=xx-8:15 date

#show current date in GMT+8 and current date – 15 mins and current date + 15 mins

echo "current date=$(date)" && echo "current - 15 mins=$(TZ=xx-7:45 date)" && echo "current + 15 mins=$(TZ=xx-8:15 date)"

#find all pdf files under the current path (include all sub directories) and listing them for output

search_files='*.pdf' && find . -name "${search_files}" -exec ls -lrt {} \;

#find all process with java keyword

search_kw='java' && ps -ef | grep ${search_kw} | grep -v 'grep'