Sources for celebrating Yom Holedes:
On a person’s yom holedes – mazolo gover, Yerushalmi Rosh Hashana ch. 3, h. 5 and see korbon ha’eida there;
Ben Is Chai, vol 1, parshas R’ay;
Especially by Tzaddikim (v’amaich kulom tzadikim):
Tanchuma end of P’ P’kudei (re: Yitchok);
Mgilah 13b (re: Moshe);
Shmos Rabbah ch 15, 9 (re: ben melech);
Rosh Hashana 11a (re: entire month avos were born in);
(See also R’sisay Laylah from Hagoan R’ Tzodok Hakohen of Lublin, kuntres Divrei Chalomos ss. 20, motzei shabbos Vayishlach year u’brochos).