Manglik dosha is read when Mangal sits in the first, fourth, seventh, eighth or twelfth house. Families notice it as alliances that reach discussion and then dissolve, or as a sharpness in the household that no one can quite place.
The Puranas name Ujjain as the birthplace of Mangal, and Mangalnath Mahadev stands at that sthaan. The Special Pujas below — the Bhaat puja and the Mangal-Bal maha abhishek — are performed there on a tithi you choose, in your naam-gotra.
5 sevas at 4 Teerth Kshetras — you choose the tithi.
That is a family decision, not one this platform makes. What the tradition offers is the shanti-vidhi for the dosha, performed at the kshetra named for Mangal. The free matching tool on this site will show whether the dosha is present in either chart.
The 5 sevas here are Special Pujas — you choose the tithi yourself at checkout, so they are available year-round and are not tied to a fixed festival date.