Add some specific time while using the linux comma

Question

In linux, date can help me to print the current time. If want to print the current time + 1 hour, what option should I give?

Answer 1

According this source you can just do:

date --date='1 hour'

Answer 2

Linux and macOS in a single command

If you need to write scripts that work on both Linux servers and macOS workstations, you can silence the error of the first date call and 'OR' it (||) with the other. It doesn't matter which comes first.

date -u -d "+${max_age}Seconds" +"%Y-%m-%dT%H:%M:%SZ" 2>/dev/null || \
date -u -v "+${max_age}S"       +"%Y-%m-%dT%H:%M:%SZ"

For example, this bash function uploads a file to AWS S3 and sets a Expires: and Cache-Control: headers.

s3_upload_cache_control(){
  local max_age_seconds="${1}" ;shift         # required
  local bucket_path="${1}"     ;shift         # required
  local filename="${1}"        ;shift         # required
  local remote_filename="/${1:-${filename}}"  # optional
  local fmt="+%Y-%m-%dT%H:%M:%SZ"
  aws s3 cp                                                          \
    "${filename}"                                                    \
    "s3://${bucket_path}${remote_filename}"                          \
    --expires                                                  "$(   \
      date -u -d "+${max_age_seconds}Seconds" $fmt 2>/dev/null  ||   \
      date -u -v "+${max_age_seconds}S"       $fmt               )"  \
    --cache-control max-age=$max_age,public                          \
    --acl public-read
}

Answer 3

In shell script, if we need to add time then use below command and date format(PUT TIME before DATE string)

date -d"11:15:10 2017-02-05 +2 hours" +"%Y-%m-%d %H:%M:%S" this will output 2017-02-05 13:15:10

THis does not result in correct date without UTC it does not work

Answer 4

TZ=Asia/Calcutta date should work (obviously this will get you the time in Calcutta).

This changes your TimeZone (TZ) environment variable for this operation only, it won't permanently set you to the new time zone you specify.

Answer 5

We can get it using below code, i was handling a case wherein i required to traverse dates from last 3 months, i used below code to traverse the same

!/bin/sh

for i in {90..1}
  do
   st_dt=$(date +%F' 00:00:00'  -d "-$i days")
   echo $st_dt
   j=$((i-1))
   end_dt=$(date +%F' 00:00:00'  -d "-$j days")
   echo $end_dt
  done

Answer 6

On Linux

Just use -d (or --date) to do some math with the dates:

date -d '+1 hour' '+%F %T'
#    ^^^^^^^^^^^^

For example:

$ date '+%F %T'
2013-04-22 10:57:24
$ date -d '+1 hour' '+%F %T'
2013-04-22 11:57:24
#           ^

On Mac OS

Warning, the above only works on Linux, not on Mac OS.

On Mac OS, the equivalent command is

date -v+1H