Today, the 14th of Iyar is Pesach Sheni. According to many opinions one does not fast on this day, make Hespedim, or a Hakomas Matzeivah. Piskei Tshuvos 492:1
There are different minhagim regarding the saying of Tachnun, (El Erech Apayim), and Lamenatzeach on Pesach Sheni (as the Shulchan Aruch does not mention to omit these tefillos). Many have the minhag to eat Matzah on Pesach Sheni by day, zecher L’korbon Pesach. Piskei Tshuvos 492:1, see also Shaarei Tshuva @ SA 131:19
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I have yahrzeit on Pesach Sheni, and as far as I know, no shul says Tachnun on this day. Regarding matzah, one blogger mentioned it would be a good idea to eat the “Korech” sandwich as Hillel did with roast lamb (as that was forbidden on the first Pesach!
FYI — The minhag of our Kehilla actually IS to say Tachnun today.
Some Kehillos have the minhag to not say Tachnun on both the 14th and 15th of Iyyar.
The Roedelheim siddur used by Khal Adath Jesahurun of Washington Heights, formerly of Frankfurt am Main makes no mention of omitting Tachnun on Pesach Sheni. On 15 Shevat & 15 Av, Tachnun is only omitted at Shachrith, according to the Roedelheim siddur.