Intelligent Dynamic Date Ticks

** Update: The archive now includes a new function setDateAxes which can be used like SET to set the properties of date axes (such as XLim) and have the tick labels update automatically. For example,
setDateAxes(gca, 'XLim', [datenum('July 1, 2008') datenum('August 1, 2008')])
** Update: DynamicDateTicks now supports an arbitrary day/month date formats. Use the third input argument to specify this: dynamicDateTicks([], [], 'dd/mm');

DYNAMICDATETICKS is a wrapper function around DATETICK which creates dynamic date tick labels for plots with dates on the X-axis. Features include:

* Smart ticks: Include year/month/day information on specific ticks as appropriate.
* Dynamic ticks: Ticks update as the plot is panned or zoomed
* Scaling ticks: Ticks change format as the timescale changes (from years to seconds).
* Support for multiple axes: Supports any combination of date and non-date axes as well as linked axes
* Date-friendly data tips: Dates displayed correctly on data cursors.

USAGE:

dynamicDateTicks()
makes the current axes a date axes with dynamic properties

dynamicDateTicks(axH)
makes all the axes handles in vector axH dynamic date axes

dynamicDateTicks(axH, 'linked')
additionally specifies that all the axes in axH are linked. This
option should be used in conjunction with LINKAXES.

dynamicDateTicks(axH, 'link', 'dd/mm')
additionally specifies the format of all ticks that include both
date and month information. The default value is 'mm/dd' but
any valid date string format can be specified. The first two
options may be empty [] if only specifying format.

EXAMPLES:
load integersignal
dates = datenum('July 1, 2008'):1/24:datenum('May 11, 2009 1:00 PM');
subplot(2,1,1), plot(dates, Signal1);
dynamicDateTicks
subplot(2,1,2), plot(dates, Signal4);
dynamicDateTicks([], [], 'dd/mm');

figure
ax1 = subplot(2,1,1); plot(dates, Signal1);
ax2 = subplot(2,1,2); plot(dates, Signal4);
linkaxes([ax1 ax2], 'x');
dynamicDateTicks([ax1 ax2], 'linked')