# Reading (Day)

> Symcon documentation · English · generated on 2026-09-26  
> Index: https://www.symcon.de/en/llms.txt

Source: https://www.symcon.de/en/service/documentation/module-reference/energy/reading-day/

_Requires Symcon >= 4.2_

The module allows to select a date and then displays the respective (First/Last) counter value of that day.

### Function scope
- When the date is changed, the First/Last read counter value of the logged variable is output, depending on the value selection.

### Software installation
- Via the [Module Store](https://www.symcon.de/en/service/documentation/components/management-console/module-store/) install the module 'Reading (Day)'.

### Set up instances in IP-Symcon
- Under "Add Instance", the 'Reading (Day)' module can be found using the quick filter.
  - More information about adding instances in the [Instances documentation](https://www.symcon.de/en/service/documentation/basics/instances/)

#### Configuration Page:

| name   | description                                |
| ------ | ------------------------------------------ |
| Source | Source variable to be used as data source. |
| Value  | First/Last value of the day.               |

### status variables
The status variables/categories are created automatically. Deleting individual ones can lead to malfunctions.

#### Statusvariables

| Name          | Type          | Description                  |
| ------------- | ------------- | ---------------------------- |
| Counter value | integer/float | Value for the selected date. |

### Visualization
The Visualization is used to display the variable. A date can be selected for which the counter reading (first/last of the day) will be displayed.

## ZST_Calculate

Source: https://www.symcon.de/en/service/documentation/module-reference/energy/reading-day/zst-calculate/

`bool ZST_Calculate(int $InstanceID)`

_Requires Symcon >= 4.2_

**Parameters**

- `$InstanceID` (int): ID of the Instance

**Returns** (bool): If the command could be executed successfully, it returns __TRUE__ as result, otherwise __FALSE__.

ID of the Instance

**Example**

```text
ZST_Calculate(12345);
```