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# Period

Period represents two dates with a start and finish.

## Schema ID

`https://gobl.org/draft-0/cal/period`

## Properties

| Title | Property | Type | Description |
| - | - | - | - |
| Label | `label` | string | Label is a short description of the period. |
| Start | `start` | [cal.Date](/draft-0/cal/date) | Start indicates when this period starts. |
| End | `end` | [cal.Date](/draft-0/cal/date) | End indicates when the period ends, and must be after the start date. |

## Validation Rules

| Field | Test | Validation Code / Message |
| - | - | - |
| <small>Period</small> | <ul class="gobl-test"><li>End not before start</li></ul> | `GOBL-CAL-PERIOD-10`<br />End date must be on or after start date |
| `start` | <ul class="gobl-test"><li>Not zero</li></ul> | `GOBL-CAL-PERIOD-01`<br />Start date cannot be zero |
| `end` | <ul class="gobl-test"><li>Not zero</li></ul> | `GOBL-CAL-PERIOD-02`<br />End date cannot be zero |


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