Dates with month and day

[willem640]

Hello,

Thanks for providing this nice python package. While working with HGV EpiDocs from papyri.info, I noticed that some dates included a day and month (such as HGV21/20810.xml, with some even having multiple dates, each with year and month: HGV38/37635.xml).

I'd be happy to make a PR. A few possible solutions come to mind:

1. Keeping the date as a string and converting to a year (or floating-point year) for functions like EpiDoc.mean_date and EpiDoc.is_after.
2. Using a package like historicaldate, which supports BC dates, that can also be uncertain or within a range.
3. Including a custom date class, with year/month/day.
4. Ignoring the month and day.

Currently, the date will just be None if it's more complex than a single int.

This is one of the offending date records:
20810:

<origDate notBefore="0216-07-25" notAfter="0216-08-28">25. Juli - 28. Aug. 216</origDate>

And one with multiple possible origDates:
37635:

                    <origDate xml:id="dateAlternativeX" notBefore="0644-05" notAfter="0644-06">
                        <precision match="../@notBefore" degree="0.5"/>
                        <certainty locus="value" match="../year-from-date(@notBefore)"/>ca. Mai - Juni 644 (Jahr unsicher)</origDate>
                     <origDate xml:id="dateAlternativeY" notBefore="0659-05" notAfter="0659-06">
                        <precision match="../@notBefore" degree="0.5"/>
                        <certainty locus="value" match="../year-from-date(@notBefore)"/>ca. Mai - Juni 659 (Jahr unsicher)</origDate>

[rsdc2]

Hello!

I'm very glad you're finding PyEpiDoc helpful. Thanks very much for pointing this out, and for providing these data points to work from! I'll look into this further and get back to you asap.

Many thanks again.