Benchling supports adding date and datetime columns in the Notebook to store temporal information. These can exist both as schema field columns for entities, results, and containers, or as custom columns.

Internally, Benchling stores dates and datetimes on these objects as ISO 8601 strings, with datetimes storing the exact moment in time specified in UTC (Coordinated Universal Time). 

To allow for maximum compatibility with other spreadsheet applications like Excel, the Notebook is also able to interpret these dates and datetimes as using the 1900 date system, where dates and datetimes are represented as the number of days since December 30, 1899. This allows dates to be manipulated using arithmetic operations like + and -, as well as some formulas like MIN and MAX.

Dates

Dates in Benchling refer to abstract dates on a calendar. This means that a date value alone does not encode information about what time or timezone that date was recorded in.

Arithmetic on dates with integers will produce new dates.

However arithmetic with decimals will first convert the date to a datetime before performing the operation.

Datetimes

Datetimes in Benchling store the exact moment in time specified in UTC (Coordinated Universal Time) to ensure that a specific moment in time is identifiable no matter what timezone the data is viewed in.

This is different from some other spreadsheet applications like Excel which do not have any timezone-aware datetimes and operate with time as a pure wall clock; where every day is exactly 24 hours. This means datetime calculations in Benchling may differ from other spreadsheet applications, especially when performing arithmetic that crosses over Daylight Savings Time boundaries. This difference ensures that common scientific data, such as durations and elapsed time, is consistent and stable across timezones.

When performing arithmetic on datetimes, each 1 added or subtracted is the equivalent of 24 hours. This is most clearly observed over Daylight Savings boundaries.

Timezones

Documents store the original timezone of the user's browser that they were created in as the base timezone. Datetimes that are ambiguous and do not include timezone information (the GMT offset) will be interpreted as being in the set timezone of the document.

Note: It is not currently possible to view or change the base timezone of a document.

Datetime chips will display the UTC time in the user's current browser timezone. Text conversions of datetimes will not adjust to the browser's timezone.

See the following example where the same Entry created in Berlin is viewed in Berlin (GMT+02) vs. in Los Angeles (GMT-07).

Conversions

The document's timezone is the basis for all datetimes type conversions in the document.

When converting a date to a datetime, the datetime will be at midnight of the document's timezone.

When converting a datetime to a date, the date will be the calendar date of the datetime in the document's timezone.

Changes to Datetime Behavior

In August 2026 and as part of Validated Cloud Release 2026.4, Benchling improved datetime handling in Notebook tables to be more consistent for users working on the same entry across multiple timezones and Daylight Savings Time boundaries. These changes do not impact persisted data of existing entities, results, and containers. For more guidance on how table formula changes affect your entries, please see this help article.

If you have questions about this change in behavior, please contact Benchling Support at support@benchling.com.