> For the complete documentation index, see [llms.txt](https://guide.data.gov.sg/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://guide.data.gov.sg/user-guide/content-quality-guidelines/data-types.md).

# Data types

You are encouraged to upload data in accordance with SG-DRM data standards.

#### **Column headers**

* Only alphanumeric or these 3 special characters: .-\_
  * Ampersand (&) should be replaced by “and” if needed
* Each must be unique
  * You should not have two headers called "duration"
* All headers are in lower case
  * e.g. "rating"
* If a header contains more than one word, use underscores to combine them
  * e.g. vehicle\_type
* Units of measurement should be omitted
* Keep it to less than 25 characters
  * Full names can be stored in the schema section of the metadata file

#### **For date variables:**

| Interval    | Column name | Format      | Range of values    | Example    |
| ----------- | ----------- | ----------- | ------------------ | ---------- |
| Annual      | `year`      | YYYY        | YYYY: 1900 onwards | 2015       |
| Monthly     | `month`     | YYYY-MM     | MM: 01 to 12       | 2015-01    |
| Daily       | `date`      | YYYY-MM-DD  | DD: 01 to 31       | 2015-01-01 |
| Weekly      | `week`      | YYYY-\[W]WW | \[W]WW: W01 to W52 | 2015-W01   |
| Quarterly   | `quarter`   | YYYY-\[Q]Q  | \[Q]Q: Q1 to Q4    | 2015-Q1    |
| Half-yearly | `half_year` | YYYY-\[H]H  | \[H]H: H1 or H2    | 2015-H1    |

#### **For date-time variables:**

| Type        | Column name | Format                                                              | Example             |
| ----------- | ----------- | ------------------------------------------------------------------- | ------------------- |
| Date + time | `date_time` | <p>YYYY-MM-DD\[T]hh:mm<br><br>hh:mm+hh:mm or hh:mm:ss+hh:mm<br></p> | 2015-01-01T12:00    |
|             |             | *or* YYYY-MM-DD\[T]hh:mm:ss                                         | 2015-01-01T12:00:00 |
| Time only   | `time`      | hh:mm                                                               | 12:00               |
|             |             | *or* hh:mm:ss                                                       | 12:00:00            |

## Get in touch

Our guidelines are always up for review to give our users the best experience possible. Have more feedback or questions? [Contact us](https://form.gov.sg/6449e5c3664c1b001249acf1) and we will reach out to you as soon as we can.


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