Gets or sets whether a save of a changed document records the save as the document's most recent modification. The default is
true.
public bool UpdateModificationDate { get; set; }
ISO 32000-2 §14.3.3 and §14.3.4: "When writing the time and date of the most recent modification ... a PDF processor shall
ensure that the data in the document information dictionary and the document level metadata stream – if both are written –
are fully equivalent." When the document has changed since it was read (or since its last incremental save), the save first
sets its modification date to the engine's clock (UseTimeProvider(TimeProvider)), to the second, the way
ModificationDate does: the Info dictionary's ModDate and the XMP packet's
xmp:ModifyDate and xmp:MetadataDate. A new document (Create()) also gets its creation
date the first time it is saved. A date set through ModificationDate since the last save
is kept.
The document is changed by this, as by any other edit. A document with no change is written exactly as before, byte for byte where its objects allow.