How to convert Unix timestamp to Datetime in T-SQL

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    SELECT DATEADD(SECOND, [UnixTimestamp], '1970-01-01 00:00:00') AS Date
    FROM YourTable;

Output:

--------------------------- | Date | --------------------------- | 2020-05-18 20:27:01 |

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

Code Explanation

In this query, 'UnixTimestamp' is the column that contains the Unix timestamp value (eg 1589833621) and '1970-01-01 00:00:00' is the Unix epoch start date.
The DATEADD function adds the number of seconds specified in the 'UnixTimestamp' to the epoch date, resulting in a Date column that displays the corresponding date and time for each Unix timestamp.
In this example the Date column would contain the date 2020-05-18 20:27:01.

Convert Date to Unix timestamp in T-SQL

Other useful T-SQL date functions

Function	Description	Example
`GETDATE()`	Returns the current date and time of the system in the format 'YYYY-MM-DD HH:MM:SS.mmm'.	`GETDATE()` returns 2024-08-28 12:34:56.789
`GETUTCDATE()`	Returns the current UTC date and time in the format 'YYYY-MM-DD HH:MM:SS.mmm'.	`GETUTCDATE()` returns 2024-08-28 16:34:56.789
`DATEADD()`	Adds a specified number of time units (e.g., days, months, years) to a date.	`DATEADD(DAY, 5, '2024-08-28')` returns 2024-09-02
`DATEDIFF()`	Returns the difference between two dates as an integer in specified time units (e.g., days, months, years).	`DATEDIFF(DAY, '2024-08-28', '2024-09-02')` returns 5
`FORMAT()`	Formats a date/time value according to the specified format string.	`FORMAT(GETDATE(), 'dd/MM/yyyy')` returns 28/08/2024
`EOMONTH()`	Returns the last day of the month that contains the specified date, with an optional offset.	`EOMONTH('2024-08-28')` returns 2024-08-31
`YEAR()`	Returns the year part of a date.	`YEAR('2024-08-28')` returns 2024
`MONTH()`	Returns the month part of a date.	`MONTH('2024-08-28')` returns 8
`DAY()`	Returns the day part of a date.	`DAY('2024-08-28')` returns 28
`SWITCHOFFSET()`	Adjusts a datetimeoffset value by a specified time zone offset.	`SWITCHOFFSET('2024-08-28 12:34:56.789 +00:00', '-08:00')` returns 2024-08-28 04:34:56.789 -08:00
`SYSDATETIME()`	Returns the current date and time as a datetime2 value, with higher precision than GETDATE().	`SYSDATETIME()` returns 2024-08-28 12:34:56.7891234

Current Unix Timestamp SECONDS SINCE JAN 01 1970

Current UTC Time

2025-08-20