Data formats

Helsinki Design System suggests formats for commonly presented data to keep Helsinki services more consistent.

Date and time

Format

Helsinki services are recommended to follow the Finnish date and time locale - even if the user is using some other language. Follow these guidelines when presenting date and time in your services.

Table 1: Recommended time formats
TypeFormatNotes
Time (forms, schedules, etc.)15:00, 02:00When presenting times in forms and schedules, use leading zeros and a colon separator. A 24-hour clock is always used.
Time (in text)15.00, 2.00When presenting times in the written text, use a single dot instead of a colon separator. Leading zeros can be opted out as well. A 24-hour clock is always used.
Day, month, and year24.6.2020Date format is D.M.YYYY even if the user's locale is something else than Finnish. Leading zeros are not used for dates.
Day, month, and year (longer)24. June 2020, 24 June 2020Using the written format of the month makes the date easier to understand for different locales. Note that technically English translation omits the dot after day number.
Today, tomorrow, yesterdayToday, 12:30If talking about today, tomorrow, or yesterday, the written format is used instead of date.

Ranges

When presenting time or date ranges, consider making information simpler by leaving redundant month and year information out. Note that when presenting ranges, en dash (–) should be used instead of a standard hyphen (-).

Table 2: Recommended range formats
TypeFormatNotes
Time range (forms, schedules, etc.)12:30–16:30When presenting times in forms and schedules, use leading zeros and a colon separator.
Time range (in text)12.30–16.30When presenting times in the written text, use a single dot instead of a colon separator.
Date range2.–15. January 2020 / 2.1.–5.2.2020Year and/or month can be only written once if both dates share the same year/month.

Time zones

Automatically use the user's timezone if possible. If not available, default to Finnish time and present the time zone as follows:

Table 3: Recommended time zone formats
TypeFormatNotes
Time zoneUTC+2Leading or trailing zeroes are not recommended to be used for timezones.
Time15:00 UTC+2-
Date24. June 2020, 15:30 UTC+2-