How to convert Datetime to Unix timestamp in Shell (Bash)

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    #!/bin/bash

    # Human-readable date (2018-07-15 12:30:45)
    date_str="2018-07-15 12:30:45"
    
    # Convert Date to Unix timestamp
    unix_timestamp=$(date -d "$date_str" +%s)
    
    echo "Unix Timestamp: $unix_timestamp"

Output:

Unix Timestamp: 1692835200

Example only. There may be multiple ways to perform this operation.

Code Explanation

In this Bash example, the date_str variable holds the human-readable date '2018-07-15 12:30:45'. The date -d "$date_str" +%s command converts this date to a Unix timestamp using the +%s option, which outputs the timestamp in seconds.
The result is printed as a Unix timestamp.

Convert Unix timestamp to Date in Bash

Other useful Bash date functions

Option	Description	Example
`-d`	Parses the provided string as a date.	`date -d "2018-07-15 12:30:45"` returns Sun Jul 15 12:30:45 UTC 2018
`+%s`	Outputs the Unix timestamp (seconds since 1970-01-01).	`date -d "2018-07-15 12:30:45" +%s` returns 1531656645
`-u`	Uses UTC (Coordinated Universal Time) for the output.	`date -u` returns the current UTC time.
`+%Y-%m-%d`	Formats the date as year-month-day.	`date +%Y-%m-%d` returns 2024-08-28
`+%H:%M:%S`	Formats the time as hours:minutes:seconds.	`date +%H:%M:%S` returns 12:34:56
`+%F`	Formats the date as `YYYY-MM-DD` (ISO format).	`date +%F` returns 2024-08-28
`+%T`	Formats the time as `HH:MM:SS`.	`date +%T` returns 12:34:56
`@timestamp`	Interprets the given timestamp as a Unix timestamp.	`date -d @1514764800` returns Mon Jan 1 00:00:00 UTC 2018

Current Unix Timestamp SECONDS SINCE JAN 01 1970

Current UTC Time

2025-08-20