Preamble
PostgreSQL to_char function converts a number or date to a string.
Syntax of to_char function in PostgreSQL
to_char( value, format_mask )
Parameters and function arguments
- value – A number, a date to be converted to a string.
- format_mask – The format that will be used to convert the value to a string. The format_mask is different from whether you convert numbers or dates. Let’s have a look.
- WITH NUMBERS – With format_mask numbers can be one of the following and can be used in many combinations:
| Parameter | Explanation |
| 9 | Value (without initial zeroes) |
| 0 | Value (with leading zeros) |
| . | Decimal |
| , | Group splitter |
| PR | A negative value in angle brackets |
| С | Symbol |
| L | Symbol of currency |
| D | Decimal |
| G | Group splitter |
| MI | Minus sign (for negative numbers) |
| PL | Sign plus (for positive numbers) |
| SG | A plus/minus sign (for positive and negative numbers) |
| RN | Roman numerals |
| TH | Serial number suffix |
| th | Serial number suffix |
| V | Shift in numbers |
| EEEE | Scientific notation |
With dates
With dates, format_mask can be one of the following and can be used in many combinations.
| Parameter | Explanation |
| YYYY | 4-digit year |
| Y,YYY | 4-digit semicolon year |
| YYY YY Y |
Last 3, 2 or 1 digit (and) years |
| IYYY | The 4-digit year according to ISO standard |
| IYY IY I |
Last 3, 2 or 1 digit(s) of ISO year |
| Q | A quarter of the year (1, 2, 3, 4; JAN-MAR = 1) |
| ММ | Month (01-12; JAN = 01) |
| MON | Abbreviated name of the month in upper case |
| Mon | Abbreviated name of the month with a capital letter |
| mon | Abbreviated name of the month in lower case |
| MONTH | The name of the month in capital letters, completed with spaces up to 9 characters long |
| Month | The name of the month with a capital letter, supplemented with spaces up to 9 characters long |
| month | The name of the month in lowercase letters, supplemented with spaces up to 9 characters long |
| RM | One month with Roman numerals |
| rm | Month in lowercase Roman numerals |
| WW | Week of the year (1-53), where week 1 begins on the first day of the year |
| W | Week of the month (1-5), where week 1 begins on the first day of the month |
| IW | ISO Week of the year (01-53) |
| DAY | The name of the day in capital letters, completed with spaces up to 9 characters long |
| Day | The name of the day with a capital letter, completed with spaces up to 9 characters long |
| day | The name of the day in lowercase letters, completed with spaces up to 9 characters long |
| DY | Abbreviated name of the day in upper case |
| Dy | Abbreviated name of the day with a capital letter |
| dy | Abbreviated name of the day in lowercase letters |
| DDD | Day of the year (1-366) |
| IDDD | Day of the year based on ISO year |
| DD | Day of the month (01-31) |
| D | Day of the week (1-7, where 1 = Sunday, 7 = Saturday) |
| ID | Day of the week based on ISO year (1-7, where 1 = Monday, 7 = Sunday) |
| J | Julian day; the number of days from midnight November 24, 4714 BC. |
| HH | One o’clock of the day (01-12) |
| HH12 | One o’clock of the day (01-12) |
| HH24 | One o’clock of the day (00-23) |
| MI | One minute (00-59) |
| SS | One second (00-59) |
| MS | Millisecond (000-999) |
| US | Microsecond (000000-999999) |
| SSSS | Seconds after midnight (0-86399) |
| am, AM, pm, or PM | Meridian Indicator |
| a.m., A.M., p.m., or P.M. | Meridian Indicator |
| ad, AD, a.d., or A.D | AD indicator |
| bc, BC, b.c., or B.C. | BC Indicator |
| TZ | Name of the time zone in upper case |
| tz | Name of the time zone in lower case |
| CC | 2-digit century |
The to_char function can be used in future versions of PostgreSQL
PostgreSQL 11, PostgreSQL 10, PostgreSQL 9.6, PostgreSQL 9.5, PostgreSQL 9.4, PostgreSQL 9.3, PostgreSQL 9.2, PostgreSQL 9.1, PostgreSQL 9.0, PostgreSQL 8.4.
Let’s take a look at some examples of to_char functions to see how to_char can be used in PostgreSQL.
Example with numbers
Below are numerical examples of the to_char function.
SELECT to_char(1918, '9999.99');
--Result: 1918.00
SELECT to_char(1814.7, '9G999.99');
--Result: 1,814.70
SELECT to_char(1810.7, 'L9G999.99'); -Result: 1,814.70;
--Result: $ 1,810.70
SELECT to_char(1810.7, 'L9G999');
--Result: $ 1,811
SELECT to_char(141, '9 9 9');
--Result: 1 4 1
SELECT to_char(123, '00999');
--Result: 00123
Example with dates
Below are examples of the dates of the to_char function.
SELECT to_char(date '2019-04-23', 'YYYY/MM/DD');
--Result: 2019/04/23
SELECT to_char(date '2019-04-23', 'MMDDYY');
--Result: 042319
SELECT to_char(date '2019-04-23', 'Month DD, YYYYY');
--Result: April 23, 2019
About Enteros
Enteros offers a patented database performance management SaaS platform. It proactively identifies root causes of complex business-impacting database scalability and performance issues across a growing number of clouds, RDBMS, NoSQL, and machine learning database platforms.
The views expressed on this blog are those of the author and do not necessarily reflect the opinions of Enteros Inc. This blog may contain links to the content of third-party sites. By providing such links, Enteros Inc. does not adopt, guarantee, approve, or endorse the information, views, or products available on such sites.
Are you interested in writing for Enteros’ Blog? Please send us a pitch!
RELATED POSTS
Keeping Operations Running at Scale: Enteros’ AIOps-Driven Database Performance Platform
- 27 January 2026
- Database Performance Management
Introduction In manufacturing plants and insurance enterprises alike, operational continuity is non-negotiable. A delayed production schedule, a failed claims transaction, or a slow underwriting system can ripple into lost revenue, regulatory exposure, and eroded customer trust. At the heart of these operations sit databases—quietly powering everything from shop-floor automation and supply chain planning to policy … Continue reading “Keeping Operations Running at Scale: Enteros’ AIOps-Driven Database Performance Platform”
Managing Real Estate Data at Scale: Enteros AI Platform for Database Performance and Cost Estimation
Introduction The real estate sector has undergone a dramatic digital transformation over the past decade. From commercial real estate (CRE) platforms and property management systems to residential marketplaces, smart buildings, and PropTech startups, modern real estate enterprises are now fundamentally data-driven organizations. Behind digital leasing platforms, pricing engines, tenant experience apps, IoT-enabled buildings, analytics dashboards, … Continue reading “Managing Real Estate Data at Scale: Enteros AI Platform for Database Performance and Cost Estimation”
Governing AI Performance in Technology Enterprises: Enteros GenAI-Driven Intelligence Platform
- 26 January 2026
- Database Performance Management
Introduction Artificial Intelligence has moved from experimentation to the core of modern technology enterprises. AI now powers customer experiences, revenue optimization, fraud detection, personalization engines, autonomous operations, developer productivity tools, and mission-critical decision systems. From SaaS platforms and digital marketplaces to enterprise software and AI-native startups, organizations are embedding AI into nearly every layer of … Continue reading “Governing AI Performance in Technology Enterprises: Enteros GenAI-Driven Intelligence Platform”
Optimizing Healthcare Databases at Scale: How Enteros Aligns GenAI, Performance Intelligence, and Cloud FinOps
Introduction Healthcare organizations are under unprecedented pressure to deliver better patient outcomes while operating within increasingly constrained financial and regulatory environments. Hospitals, payer networks, life sciences companies, and digital health platforms now rely on massive volumes of data—electronic health records (EHRs), imaging repositories, genomics pipelines, AI-driven diagnostics, claims systems, and real-time patient monitoring platforms. At … Continue reading “Optimizing Healthcare Databases at Scale: How Enteros Aligns GenAI, Performance Intelligence, and Cloud FinOps”