Question:
If one left davening early on Monday or Thursday and did not say Tachanun at all, does he need to say it later in the day (until shkia)?
Answer:
If one didn’t say Vhu Rachum during shacharis he should say it later on in the day, this is because it doesn’t have a specific time that it must be said. (But of course it is better to say it when it is supposed to be said).
Sources:
Rivvos Ephraim vol 7 61-2.
