icalendarrfc5545webcal

What are the meanings of the DURATION string parts of RFC 5545?


http://icalendar.org/iCalendar-RFC-5545/3-3-6-duration.html - this is the reference to the document. It is somewhat self explanatory, but still a little bit hard to grasp. Maybe someone could explain what does the P in P15DT5H0M20S stand for? Also, maybe there is some other code-character that can be substituted for the P. If so, what are the other characters?


Solution

  • To understand the grammar, you might want to refer to the actual RFC 5545 section. Extract given below:

    3.3.6. Duration Value Name: DURATION

    Purpose: This value type is used to identify properties that contain a duration of time.

    Format Definition: This value type is defined by the following notation:

      dur-value  = (["+"] / "-") "P" (dur-date / dur-time / dur-week)
    
       dur-date   = dur-day [dur-time]
       dur-time   = "T" (dur-hour / dur-minute / dur-second)
       dur-week   = 1*DIGIT "W"
       dur-hour   = 1*DIGIT "H" [dur-minute]
       dur-minute = 1*DIGIT "M" [dur-second]
       dur-second = 1*DIGIT "S"
       dur-day    = 1*DIGIT "D"
    

    from the standard, you can see that the letter P is an integral part of the grammar and that no other letter is considered.