Today, erev Rosh Chodesh Sivan, is the day that the Shlo"h wrote is especially important for the prayer he composed, known as Tefillas HaShloh, for a parent to say on behalf of his children that they should be righteous and God-fearing. 
This prayer can, of course, be said any and every day, but the Shloh pointed to erev Rosh Chodesh Sivan as the day of extra significance for this praye.


If the image above is too hard to read, Artscoll has an image of the tefilla on their website...

A local organization even paid to call local residents playing a recorded message reminding people to say the prayer of the Shloh, and offering to do it on your behalf with a minyan of talmidei chachomim for a donation.