Bash Script: Difference in Minutes Between Two Times

Bash script: difference in minutes between two times

A pure bash solution :

old=09:11
new=17:22

# feeding variables by using read and splitting with IFS
IFS=: read old_hour old_min <<< "$old"
IFS=: read hour min <<< "$new"

# convert hours to minutes
# the 10# is there to avoid errors with leading zeros
# by telling bash that we use base 10
total_old_minutes=$((10#$old_hour*60 + 10#$old_min))
total_minutes=$((10#$hour*60 + 10#$min))

echo "the difference is $((total_minutes - total_old_minutes)) minutes"

Another solution using date (we work with hour/minutes, so the date is not important)

old=09:11
new=17:22

IFS=: read old_hour old_min <<< "$old"
IFS=: read hour min <<< "$new"

# convert the date "1970-01-01 hour:min:00" in seconds from Unix EPOCH time
sec_old=$(date -d "1970-01-01 $old_hour:$old_min:00" +%s)
sec_new=$(date -d "1970-01-01 $hour:$min:00" +%s)

echo "the difference is $(( (sec_new - sec_old) / 60)) minutes"

See http://en.wikipedia.org/wiki/Unix_time

How to calculate time elapsed in bash script?

Bash has a handy SECONDS builtin variable that tracks the number of seconds that have passed since the shell was started. This variable retains its properties when assigned to, and the value returned after the assignment is the number of seconds since the assignment plus the assigned value.

Thus, you can just set SECONDS to 0 before starting the timed event, simply read SECONDS after the event, and do the time arithmetic before displaying.

#!/usr/bin/env bash

SECONDS=0
# do some work
duration=$SECONDS
echo "$(($duration / 60)) minutes and $(($duration % 60)) seconds elapsed."

As this solution doesn't depend on date +%s (which is a GNU extension), it's portable to all systems supported by Bash.

Shell: How to compare two Time strings and return difference in minutes?

Convert your times to epoch and calculate seconds. I assume that you don't get your times from date because if so you can just format with "+%s" to get the epoch time immediately. The answer assumes you just have two strings with %H%M.

So, assign your strings with the timestamp (hour and minute)

current_utc_time=$(date +"%H%M")
sch_time=$(date +"18%M")

Convert to unix timestamp.

macOS

epoch_current=$(date -j -f "%H%M" "$current_utc_time" +%s)
epoch_sch=$(date -j -f "%H%M" "$sch_time" +%s)

Linux

epoch_current=$(date --date "$current_utc_time" +%s)
epoch_sch=$(date --date "$sch_time" +%s)

Calculate your diff (in minutes).

diff_in_minutes=$(( ($epoch_sch - $epoch_current) / 60 ))

how to calculate the total minutes between two dates?

echo $((($(date -ud "$date2" +'%s') - $(date -ud "$date1" +'%s'))/60)) minutes
 

Calculate the difference between two timestamps in bash

What about this?

#!/usr/bin/env bash
echo "BASH_VERSION:" $BASH_VERSION 

line="2020-05-21 05:52:47;2020-05-28 19:37:36"
IFS=';' read -a dates <<< $line
startDatetime=${dates[0]}
endDatetime=${dates[1]}

echo "| dates -> " ${dates[@]}
echo "|> startDatetime -> ${startDatetime}"
echo "|> endDatetime -> ${endDatetime}"

startTime=$(date -jf "%Y-%m-%d %H:%M:%S" "${startDatetime}" +%s)
endTime=$(date -jf "%Y-%m-%d %H:%M:%S" "${endDatetime}" +%s)
diffSeconds="$(($endTime-$startTime))"

echo "Diff in seconds: $diffSeconds"
# at this point you have the diff in seconds and you can parse it however you want :)

diffTime=$(gdate -d@${diffSeconds} -u +%H:%M:%S) # you'll need `brew install coreutils`
echo "Diff time(H:M:S): $diffTime"

Output:

BASH_VERSION: 5.0.17(1)-release
| dates ->  2020-05-21 05:52:47 2020-05-28 19:37:36
|> startDatetime -> 2020-05-21 05:52:47
|> endDatetime -> 2020-05-28 19:37:36
Diff in seconds: 654289
Diff time(H:M:S): 13:44:49

To install the latest bash I found this medium post.

Note: If this doesn't work because some version incompatibilities with the date function, for example, the idea should be pretty similar and you could find a workaround that adapts to your current version, I'm sure. Logically, the easiest solution I see is:

1st) Split the string into two: one for each DateTimes.

2nd) Transform each DateTime from string to dates.

3rd) Apply a diff between these dates: using the seconds from each.

4th) Having the diff seconds you can display it as you want (year, days, minutes, seconds)

Bash script to calculate time difference

I guess you are just having difficulties to formulate the loop in bash syntax. Here you go:

#!/bin/bash
START_TIME=10:46:20
TIME_Record=(
11:03:00
11:24:00
11:27:00
11:32:00
)
SEC1=$(date +%s -d "${START_TIME}")
for d in "${TIME_Record[@]}"
do
  SEC2=$(date +%s -d "$d")
  DIFFSEC=$(( SEC2 - SEC1 ))
  echo "$DIFFSEC"
done

Calculate the time difference in minutes between two time values

You should calculate the time difference first, then do the logic. That way you can always show the difference regardless of the outcome of the test. To do the difference, convert to some common base like seconds or minutes, then format however suits for presentation, e.g.

function getTimeDiff(h1, m1, s1, h2, m2, s2) {

  return diff =  toSeconds(h2, m2, s2) - toSeconds(h1, m1, s1);  

}


function toSeconds(h, m, s) {

  return h*3600 + m*60 + s*1;

}


function secondsToHMS(secs) {

  function z(n){return (n<10? '0':'') + n}

  return z(secs/3600|0) + ':' +

         z((secs%3600)/60|0) + ':' +

         secs%60;

}


// Tests

[[4,23,15, 5,5,8],    // 04:23:15 vs 05:05:08

 [4,23,15, 4,25,8]].  // 04:23:15 vs 04:25:08

  forEach(function(arr) {

    var diff = getTimeDiff(...arr);

    console.log(`Diff of ${secondsToHMS(diff)} is ${diff > 600? 'more':'less'} than 10 minutes`);

 });