Command to get time in milliseconds

Solution 1:

date +"%T.%N" returns the current time with nanoseconds.
```
06:46:41.431857000
```
date +"%T.%6N" returns the current time with nanoseconds rounded to the first 6 digits, which is microseconds.
```
06:47:07.183172
```
date +"%T.%3N" returns the current time with nanoseconds rounded to the first 3 digits, which is milliseconds.
```
06:47:42.773
```

In general, every field of the date command's format can be given an optional field width.

Solution 2:

date +%s%N returns the number of seconds + current nanoseconds.

Therefore, echo $(($(date +%s%N)/1000000)) is what you need.

Example:

$ echo $(($(date +%s%N)/1000000))
1535546718115

date +%s returns the number of seconds since the epoch, if that's useful.

Solution 3:

Nano is 10⁻⁹ and milli 10⁻³. Hence, we can use the three first characters of nanoseconds to get the milliseconds:

date +%s%3N

From man date:

%N nanoseconds (000000000..999999999)

%s seconds since 1970-01-01 00:00:00 UTC

Source: Server Fault's How do I get the current Unix time in milliseconds in Bash?.

Solution 4:

On OS X, where date does not support the %N flag, I recommend installing coreutils using Homebrew. This will give you access to a command called gdate that will behave as date does on Linux systems.

brew install coreutils

For a more "native" experience, you can always add this to your .bash_aliases:

alias date='gdate'

Then execute

$ date +%s%N

Solution 5:

Here is a somehow portable hack for Linux for getting time in milliseconds:

#!/bin/sh
read up rest </proc/uptime; t1="${up%.*}${up#*.}"
sleep 3    # your command
read up rest </proc/uptime; t2="${up%.*}${up#*.}"

millisec=$(( 10*(t2-t1) ))
echo $millisec

The output is:

This is a very cheap operation, which works with shell internals and procfs.