Get Hour from Timestamp(datetime) in PostgreSQL

In order to get hour from Timestamp in postgresql we use Extract() function. Within the Extract keyword we have to mention HOUR as we are getting HOUR from timestamp. In addition to Extract() function we also use DATE_PART() function To extract hour from datetime i.e. timestamp in PostgreSQL, DATE_PART() function with the ‘hour’ unit accomplishes this task.

Let’s see how to

  • Extract hour from Timestamp in Postgresql
  • Create the column which extracts hour from timestamp column

With an example for both

 

Extract hour from Timestamp in Postgresql:

Within the Extract keyword we have to mention HOUR as we are getting hour from timestamp

SELECT EXTRACT (HOUR FROM TIMESTAMP '2011-11-22 13:30:15')

So the resultant HOUR will be

Get Hour from timestamp in Postgresql 2

 

 

Syntax for DATE_PART() Function in PostgreSQL:


DATE_PART(unit, source)

unit: Specifies the part of the date or timestamp to extract (e.g., ‘year’, ‘month’, ‘day’, ‘hour’, ‘minute’, ‘second’, etc.).

source: The date or timestamp from which to extract the specified part

In Our case. The values of the unit must be “hour”.

 

Extract hour from datetime(timestamp) in PostgreSQL Simple Example:

In order to Extract hour from datetime (timestamp) in postgresql we will be using DATE_PART() function.

In the below Example we will be passing hour as “unit” argument and datetime as “source” argument in order to extract hour from Date or datetime

SELECT DATE_PART('hour', '2024-02-24 15:30:45.123456'::timestamp) AS hour_part;

Output:

Extract-hour-from-datetime-timestamp-in-postgresql-1

 

 

Extract hour from Current date in postgresql :

This query uses the CURRENT_TIMESTAMP function to get the current datetime and then extracts the hour using DATE_PART()

SELECT CURRENT_TIMESTAMP AS current_datetime, DATE_PART('hour', CURRENT_TIMESTAMP) AS hour;

Output:

Extract-hour-from-datetime-timestamp-in-postgresql-2

 

 

 

Extract hour from Date in postgresql table using DATE_PART():

We will be using  Below Student_detail table for our example to depict on how to extract hour from date in postgresql

Student_detail:

Extract-hour-from-datetime-timestamp-in-postgresql-3

In the above table we will be using  DATE_PART() Function, which will take “hour” and column named “birthdaytime” as argument. Which will extract hour from “birthdaytime” column and store in the new column of postgresql table as shown below

select *, DATE_PART('hour', birthdaytime::timestamp) AS hour from Student_detail

so the resultant table will have hour column

Extract-hour-from-datetime-timestamp-in-postgresql-4

 

 

Extract hour from Date in postgresql table using Extract():

We will be using Below Student_detail table for our example to depict on how to extract hour from date in postgresql

Student_detail:

Extract-hour-from-datetime-timestamp-in-postgresql-3

In the above table we will be using  EXTRACT() Function, which will take “hour” and column named “birthdaytime” as argument. Which will extract hour from “birthdaytime” column and store in the new column of postgresql table as shown below

Select *, extract(HOUR FROM birthdaytime) as hour from student_detail

So the resultant table will have hour column

Extract-hour-from-datetime-timestamp-in-postgresql-6

 

 

 

                                                                                                 

Author

  • Sridhar Venkatachalam

    With close to 10 years on Experience in data science and machine learning Have extensively worked on programming languages like R, Python (Pandas), SAS, Pyspark.

    https://www.linkedin.com/in/sridhar-venkatachalam-74414252/ karaimadai@sg2plcpnl0204.prod.sin2.secureserver.net Venkatachalam Sridhar