Time plays a crucial role in FLOW, both in traffic event analysis and in data export for further processing. Understanding time modes and the format of exported data is essential for accurate insights and interpretation.
Time Modes
When working with widgets in FLOW, you can select data using different Time Modes, depending on what kind of trajectory data you want to retrieve:
Now: selects trajectories that are occurring at the present moment. It returns entire trajectories.
Whole history: selects all trajectories recorded in the system, or its current cache.
Offset: selects trajectories occurring within a sliding time window, defined by a start and end offset from the current time.
Time blocks: selects trajectories occurring in defined fixed-length time blocks (e.g., 15 minutes, 1 hour). You can choose:
Current time block
Previous time block
Custom (e.g., last 5 blocks)
Time Conversion
When exporting trajectory or event data, time related data (time stamps) are stored in UNIX time format in milliseconds, which is a standard format in computing (milliseconds since 1.1.1970).
To convert UNIX time in Excel to a readable date and time format, use this formula:
TIME = ((A1 + 3600000) / 86400000) + DATE(1970, 1, 1)
Where:
A1 is the cell containing the UNIX timestamp in milliseconds.
3600000 is one hour in milliseconds (adjust based on time zone; for UTC+2 use 7200000).
86400000 is the number of milliseconds in one day.
Make sure to format the result cell as hh:mm:ss or dd.mm.yyyy hh:mm:ss for correct display.
For example, the value 1605250440905 converts to 13.11.2020 07:54:01.