How widespread is adoption of ISO 8601, the standard for date and time formats? Is your company aligned?
I see ISO 8601 widely used in scientific fields, software development, and more and more international correspondence. Yet, I think its fair to say the adoption in pharma has been lacking. So I am really curious, has your organization fully or partially adopted it? If so, how did it go?
Date Format
The basic principle of ISO 8601 for dates is to represent them in a descending order of significance:
- Complete date: YYYY-MM-DD (extended format) or YYYYMMDD (basic format)
Example: 2022-09-27 or 20220927 - Year and month: YYYY-MM
Example: 2022-09 - Year only: YYYY
Example: 2022
Time Format
ISO 8601 defines the following time format:
- Basic format: Thhmmss
- Extended format: Thh:mm:ss
Where:
- T is the time designator
- hh represents hours (00-24)
- mm represents minutes (00-59)
- ss represents seconds (00-60, where 60 is used for leap seconds)
Example: T134730 or T13:47:30 represents 1:47:30 PM
Combined Date and Time
ISO 8601 allows combining date and time representations:
- YYYY-MM-DDThh:mm:ss or YYYYMMDDThhmmss
Example: 2022-09-26T07:58:30 represents September 26, 2022, at 7:58:30 AM
Time Zone Designators
The standard also specifies how to represent time zones:
- Z: Represents UTC (Coordinated Universal Time)
- ±hh:mm or ±hhmm: Represents the offset from UTC
Example: 2022-09-07T15:50+00:00 or 2022-09-07T15:50Z represents 3:50 PM UTC on September 7, 2022.
Key Features
- The standard uses the Gregorian calendar.
- It employs a 24-hour clock system.
- All elements are represented by a fixed number of digits, zero-padded if necessary.
- The standard allows for reduced precision by omitting certain elements.
- It can represent dates, times, time intervals, and recurring time intervals
Government and Official Use
Many countries have officially adopted ISO 8601 as their recommended or mandated date format for government and official use. For example:
- The UK government has mandated the use of ISO 8601 for IT systems, APIs, and machine-to-machine communication.
- Canada’s government and Standards Council officially recommend ISO 8601 for all-numeric dates.
- Australia recommends ISO 8601 as the short date format for government publications.
The European Union has adopted ISO 8601 as the European Standard EN 28601, making it valid in all EU countries.
Has anyone seen Health Canada or an EMA (and/or national competent authority) push back at a time/date not in ISO 8061 format? I think there has been a lot of push back in health care around adoption, for example the NHS in the UK uses 01-JAN-2017 for medicine labels even though the UK has adopted ISO 8061.
I find it fascinating that the eCTD specification does not mandate a specific date format for metadata or content within submissions, allowing flexibility for regional requirements. Yet we have seen many health authorities that have implemented eCTD do recommend or require the use of ISO 8601 date formats in certain contexts:
- The US FDA guidance on eCTD recommends using ISO 8601 format (YYYY-MM-DD) for dates in the submission.
- The EU guidance on eCTD also recommends ISO 8601 format for dates in certain metadata fields.
The eCTD XML backbone uses the W3C XML Schema date and dateTime datatypes, which are based on ISO 8601 formats. While not explicitly requiring ISO 8601, the eCTD specification does emphasize the importance of consistent and unambiguous date representations, which aligns with the goals of ISO 8601. It really makes me wonder when this decision will start rippling through other parts of the industry.
I’d love your thoughts.

I suppose the question is, adopted for what?
In digital systems of our own design, we use YYYYMMDD because it would be crazy to use anything else. When we write our own code, this format is simply easier to work with, even if the date will be displayed to the user in a different format.
But forcing all systems, procedures, and processes to comply with this is a needless change with close to zero value add.
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