Days of productive life remaining. Demo

Download, chmod +x stat-mori.fish and put it in your PATH
fish is required to run this script, but doesn't have to be your SHELL to do it.
| #!/usr/bin/env fish | |
| # lifetimer 3000 weeks where 1/2 is at 32 years of age, starts at ~3¼ y.o. | |
| # i.e: Day 8375/10,500 · 1196/1,500 weeks · 275/345 more months · (since 2016 1/31) | |
| # v0.3 gist.github.com/godDLL/b198f3311086491a5778035162653cd5 | |
| # | |
| set -q YOB ; or set -l YOB 1984 | |
| set -q DOB ; or set -l DOB 01/23 | |
| set -l NOW (string split -- ' ' (date +%Y\ %j)) | |
| set -l tDOB (string split -- '/' $DOB) | |
| set -- tDOB (math -s0 $tDOB[1]'* 30.4375 - 30.4375 + '$tDOB[2]) | |
| set -l tDTL 10,500 | |
| set -l tWKS 1,500 | |
| set -l tMOS 345 | |
| set -l BY (math -s0 $YOB' + 32') | |
| if test $BY -ge $NOW[1] | |
| set BY (math -s0 $YOB' + 17') | |
| if test $BY -ge $NOW[1] | |
| set tDOB (math -s0 $tDOB'+ 92.25') | |
| set BY (math -s0 $YOB' + 3') | |
| set tDTL 21,000 | |
| set tWKS 3,000 | |
| set tMOS 690 | |
| else | |
| set tDOB (math -s0 $tDOB'+ 228.75') | |
| set tDTL 15,750 | |
| set tWKS 2,250 | |
| set tMOS 517½ | |
| end | |
| else | |
| end | |
| set -l DTL (math -s0 (string replace -- , '' $tDTL)\ | |
| '- (('$NOW[2]'- '$tDOB')+ 365.25* ('(math $NOW[1]'- '$BY)"))") | |
| set -l WKS (math -s0 "$DTL /7") | |
| set -l MOS (math -s0 "$DTL /30.4375") | |
| switch "$argv" | |
| case '-x' | |
| echo $DTL $WKS $MOS | |
| case '-p' | |
| set -l POH (math -s2 '100/ ('(string replace -- , '' $tDTL)' /'$DTL')') | |
| echo -e \e\[2mDay \e\[m$DTL\e\[2m/$tDTL · \e\[m$WKS\e\[2m/$tWKS weeks · \e\[m$POH\e\[2m% left · \(since $BY $DOB\)\e\[m | |
| case '' | |
| echo -e \e\[2mDay \e\[m$DTL\e\[2m/$tDTL · \e\[m$WKS\e\[2m/$tWKS weeks · \e\[m$MOS\e\[2m/$tMOS more months · \(since $BY $DOB\)\e\[m | |
| case '*' | |
| echo 'USAGE: stat-mori [-x]'\n'Print a memento mori. Please set YOB and DOB.'\n\t'-p for PERCENTAGE in place of MONTHS, or'\n\t'-x for export: DAYS WEEKS MONTHS' >&2 | |
| end #switch | |
v0.3 added percentage

If you're over 32 percentage drops 0.01% every day, except for every 21st day.