Function Repository Resource:

DateAmbiguityBreak

Source Notebook

Interpret date strings by specifying how ambiguity should be handled

Contributed by: Sjoerd Smit

ResourceFunction["DateAmbiguityBreak"]["DayFirst"][string]

interprets string as a DateObject, using a day-before-month interpretation if there is ambiguity.

ResourceFunction["DateAmbiguityBreak"]["MonthFirst"][string]

interprets string as a DateObject, using a month-before-day interpretation if there is ambiguity.

ResourceFunction["DateAmbiguityBreak"][{elem₁,elem₂,elem₃}][string]

specifies a custom day-month-year pattern for prioritization.

ResourceFunction["DateAmbiguityBreak"][Function[…]][string]

applies a function to an Association holding all possible interpretations and ambiguity data.

ResourceFunction["DateAmbiguityBreak"][Interpreter[…], pattern][string]

uses the specified Interpreter to interpret string.

Details

ResourceFunction["DateAmbiguityBreak"] is intended as an extension of the default auto-magic Wolfram date interpretation functionality that will just "do the right thing" for nearly every input, since the month-first or day-first ambiguity is usually the only source of ambiguity encountered in practice.

ResourceFunction["DateAmbiguityBreak"][pattern] uses Interpreter["Date"|"DateTime"] to interpret the input.

Dates like "2022-01-02" will always be assumed to be in year-month-day form.

Any date that's completely unambiguous (like "15-08-2022") will always be interpreted irrespective of the pattern specified.

If the year specification is ambiguous because it's given by only two digits, the year-last interpretation is used since the ISO standard mandates four year digits and does not accommodate the yy-mm-dd format.

ResourceFunction["DateAmbiguityBreak"] threads over lists of dates.

Examples

Basic Examples (2)

Interpret an ambiguous date string:

In[1]:=

Out[1]=

Interpret ambiguous strings with date and time information:

In[2]:=

Out[2]=

In[3]:=

Out[3]=

Strings in year-first form are always assumed to be in the ISO standard year-month-day form:

In[4]:=

Out[4]=

In[5]:=

Out[5]=

In[6]:=

Out[6]=

Scope (4)

Interpret multiple strings at a time:

In[7]:=

Out[7]=

Specify your own preferred formats to break ambiguity:

In[8]:=

ResourceFunction[
"DateAmbiguityBreak", ResourceSystemBase -> "https://www.wolframcloud.com/obj/resourcesystem/api/1.0"][{"Year", "Day", "Month"} | {"Month", "Day", "Year"}][
{"2022-03-08", "08-03-2022"}
]

Out[8]=

Specify a custom function to apply to the ambiguity data in the form of an Association to make it easier to pick compatible interpretations:

In[9]:=

Out[9]=

In[10]:=

ResourceFunction[
"DateAmbiguityBreak", ResourceSystemBase -> "https://www.wolframcloud.com/obj/resourcesystem/api/1.0"][
Function[
Select[#, Last[#Value] === "Year" &]
]
]["08-03-20"]

Out[10]=

Use a more restrictive Interpreter to parse only pure date strings:

In[11]:=

Out[11]=

Properties and Relations (2)

DateAmbiguityBreak uses an AmbiguityFunction to find the desired interpretation from an AmbiguityList:

In[12]:=

Out[12]=

Note that unambiguous strings do not get placed in an AmbiguityList.

When the year is given by only two digits, a year-last interpretation is always preferred since the ISO standard mandates four year digits. Thus, dd-mm-yy takes precedence over yy-mm-dd:

In[13]:=