# timestamp

## High-Level Explanation

Year, month, day, hour, minute, second (plus fractional second), and time zone, in the format YYYY-MM-DDThh:mm:ss.sTZD. Example:&#x20;

```
2022-12-09 07:53:23.497000+00:00
```

Where this record takes place on December 9th, 2022 at 7:53 AM (and 23.497 seconds). This record takes place at the coordinate (latitude, longitude): 42.307629, -83.714811, (in Ann Arbor, Michigan) which is in the "America/New\_York" time zone. Since this record occurs during standard time (not daylight savings time), the time zone is UTC-05:00.

## Enables

Conversion to local time. One potential source of time zone geospatial data is: <https://common-data.carto.com/tables/ne_10m_time_zones/public>. Note that `tz_convert` does indeed correct for daylight savings time.

{% code overflow="wrap" lineNumbers="true" %}

```python
import geopandas as gpd

tz = gpd.read_file('ne_10m_time_zones.geojson')
gdf['geometry'] = gpd.GeoSeries.from_xy(x=gdf['longitude'],y=gdf['latitude'])
gdf = gdf.sjoin(tz[['geometry','tz_name1st']])
gdf['timestamp'] = \
        gdf.apply(lambda row: row['timestamp'].tz_convert(row['tz_name1st']), \
                     axis=1)
```

{% endcode %}

## Enabled By

## Known Quirks

* It is important to note that this signal defaults to the UTC time zone and, if local time is important, the signal must be converted. See [latitude-and-longitude](https://docs.dimo.org/dimo-explorer/field-descriptions-in-detail/latitude-and-longitude "mention")for discussion of the frequency of data collection.
* Vehicles sometimes lose cellular connection for data reporting, so there can be long gaps between timestamps due to potentially lost connection, but also possibly just lack of vehicle use.&#x20;

## Visualizations with Explanations
