Time difference in a unix script?

Question

I need to write a script:

startdate = 2016-02-14 20:10:10 
enddate =   2016-02-14 23:59:59
c= 1240 (minutes)
d=10  

r = ratio(startdate - enddate) / c;

d=d*r;

How to calculate the difference between the start date and the end date?

ratio of time difference doesn't mean anything to me. Please clarify what you want. Do you want to get the number of seconds (minutes?) between those two dates, so you can compare it to $c? — Stéphane Chazelas, Oct 26 '16 at 11:15
you may want to convert the start and end date to unix time using the date command. thus, subsequent calculation are quite easy to perform. — user236012, Oct 26 '16 at 11:15

Vesa Karjalainen · Answer 1 · 2016-10-26T12:31:12.710

3

To calculate seconds between two times:

#!/bin/bash

START="2016-02-14 20:10:10"
END="2016-02-14 23:59:59"

SECS=$(echo $(date -d "$END" +%s) - $(date -d "$START" +%s) | bc)

echo $SECS

edited Oct 26 '16 at 12:31

answered Oct 26 '16 at 12:24

Vesa Karjalainen

I dont know the ratio of the start and end date is same as $(echo $(date -d "$END" +%s) - $(date -d "$START" +%s)
what is | bc in the script ?

can you please confirm me Sorry if i am asking wrong question
– AAA Oct 26 '16 at 14:01
hello my c value is minutes, I want to take the ratio of startdate-enddate then that would be divide by c minutes – AAA Oct 26 '16 at 14:10
Why the construct SECS=$(echo $(some command pipeline))? It would be far better to use SECS=$(some command pipeline) and avoid a layer of complication. – Chris Davies Oct 26 '16 at 14:15

1 Answers1