TO_CHAR for date formatting in PostgreSQL - Step-by-Step Execution

Concept Flow - TO_CHAR for date formatting

Start with a DATE or TIMESTAMP value

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Apply TO_CHAR function with format string

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TO_CHAR converts date to text

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Output formatted string

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Use result in query or display

TO_CHAR takes a date or timestamp and a format pattern, then returns a text string formatted as specified.

Execution Sample

PostgreSQL

SELECT TO_CHAR('2024-06-15'::date, 'DD Mon YYYY');

Formats the date June 15, 2024 as a string like '15 Jun 2024'.

Execution Table

Step	Input Date	Format String	TO_CHAR Output	Explanation
1	2024-06-15	'DD Mon YYYY'	'15 Jun 2024'	TO_CHAR reads date and applies format: day number, abbreviated month, full year
2	2024-06-15	'YYYY/MM/DD'	'2024/06/15'	Format changes to year/month/day with slashes
3	2024-06-15	'FMDay, DDth Month YYYY'	'Saturday, 15th June 2024'	FM removes padding, literal 'th' after day number, full month name
4	2024-06-15	'HH24:MI:SS'	'00:00:00'	Time part defaults to midnight for date input
5	2024-06-15	'YYYY-MM-DD'	'2024-06-15'	Standard ISO date format output
6				Execution ends after formatting the input date

💡 All formatting options applied, TO_CHAR returns formatted text string

Variable Tracker

Variable	Start	After 1	After 2	After 3	After 4	After 5	Final
Input Date	2024-06-15	2024-06-15	2024-06-15	2024-06-15	2024-06-15	2024-06-15	2024-06-15
Format String		'DD Mon YYYY'	'YYYY/MM/DD'	'FMDay, DDth Month YYYY'	'HH24:MI:SS'	'YYYY-MM-DD'	'YYYY-MM-DD'
TO_CHAR Output		'15 Jun 2024'	'2024/06/15'	'Saturday, 15th June 2024'	'00:00:00'	'2024-06-15'	'2024-06-15'

Key Moments - 3 Insights

Why does TO_CHAR output '00:00:00' for time when formatting a date?

Because the input is a date without time, PostgreSQL treats the time as midnight (00:00:00). See execution_table row 4.

What does 'FM' do in the format string?

'FM' removes padding spaces from the output, so day and month names are not padded. See execution_table row 3.

Why is the output a text string and not a date?

TO_CHAR always returns text because it formats the date into a readable string. This is shown in all output values in execution_table.

Visual Quiz - 3 Questions

Look at the execution_table, what is the TO_CHAR output at step 2?

A '2024/06/15'

B '15 Jun 2024'

C 'Saturday, 15th June 2024'

D '00:00:00'

💡 Hint

Check the 'TO_CHAR Output' column in execution_table row 2.

At which step does the format string include an ordinal suffix like 'th'?

A Step 1

B Step 3

C Step 4

D Step 5

💡 Hint

Look for 'DDth' in the 'Format String' column in execution_table.

If the input was a timestamp with time 14:30:00, what would TO_CHAR output for format 'HH24:MI:SS'?

A '2024-06-15'

B '00:00:00'

C '14:30:00'

D '15 Jun 2024'

💡 Hint

Refer to execution_table row 4 and imagine input time is not midnight.

Concept Snapshot

TO_CHAR(date, format) converts a date or timestamp to text.
Use format patterns like DD (day), Mon (month abbrev), YYYY (year).
FM removes padding spaces.
Output is always text, not date.
Useful for readable date display in queries.

Full Transcript

TO_CHAR is a PostgreSQL function that formats dates or timestamps into readable text strings. You give it a date and a format pattern, and it returns the date as text formatted as you want. For example, 'DD Mon YYYY' turns June 15, 2024 into '15 Jun 2024'. If you use 'FM' in the format, it removes extra spaces. When you format a date without time, the time defaults to midnight '00:00:00'. The output is always text, so you can display or use it as a string in your queries.