[TalentSignal] proposal for Job Start Date

Hello all, the second relatively simple issue that we prioritized, is 
that currently schema.org/JobPosting has no way to specify the expected 
start date for the job being advertised.

A simple way to fix this 
<https://www.w3.org/community/talent-signal/wiki/Provide_start_date_for_job> 
is a new property of JobPosting:

*jobStartDate*

    *Definition: *The date on which a successful applicant for this job
    would be expected to start work. Text values such as "Immediately"
    or "As soon as possible" may be used when a specific date is not
    appropriate.

    *Expected type:* ISO 8601 Date <https://schema.org/Date> or Text
    <https://schema.org/Text>


Please let me know if you wish to improve on this or have an alternative 
suggestion. In particular, is a text value to indicate an immediate 
start sufficient, or should this be handled more explicitly, for example 
as a separate property?

On that question, my own view (as exemplified in the proposal) is that, 
while an explicit indicator for immediate start may be useful for 
internal systems, a text value is adequate for advertising this on the 
web. If experience and demand show that this approach is not adequate, 
we would have evidence to provide to schema.org for a separate, explicit 
property.

Regards, Phil.

-- 

Phil Barker <http://people.pjjk.net/phil>. http://people.pjjk.net/phil
CETIS LLP <https://www.cetis.org.uk>: a cooperative consultancy for 
innovation in education technology.
PJJK Limited <https://www.pjjk.co.uk>: technology to enhance learning; 
information systems for education.

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