Why does the Talkative Man's master say that one ought not to play the raga 'punnaga varali' at night?

Question

In the short story The Snake-Song (a part of the collection titled Malgudi Days), the Talkative Man describes an event in his youth that led to him having to abandon his music: the Talkative Man had to forsake his flute after being compelled to play a certain snake-song over and over until physical exhaustion.

The raga of the snake-song that the Talkative Man had to play is punnaga varali. It is an actual raga in the south Indian classical music tradition (known as Carnatic music). The raga is of folk origin, and has apparently been used traditionally by snake-charmers in the country. In the short story, after the Talkative Man narrates his ordeal to his master, the latter says,

Don’t you know you ought not to play punnaga varali at night?

Questions: Is this restriction on the allowed playing times for this raga a creative choice by R. K. Narayan, or is it an actual restriction found in the Carnatic music tradition? If it is an actual restriction in Carnatic music, what is/are the reason/s behind this?

I am aware that many ragas are meant to be played at certain times of the day or during certain seasons for the greatest effect. However, that seems to me to be different from forbidding a raga from being played at certain times.

Also, punnaga varali may very well have an equivalent raga in the north Indian tradition (known as Hindustani music), but I am not very knowledgeable about it. I do know that the associated times/seasons for ragas are followed more strictly in Hindustani music than in Carnatic music. So, an answer providing information from the Hindustani perspective would also be welcome, though the short story seems to be set in the southern part of India.

Of course, evidence for such a (social?) convention could come from places other than musical texts, so those are also welcome.

Answer 1

You are correct that Carnatic / South Indian classical music is not particularly concerned with associating ragas with times of day. And AFAIK there is no Hindustani / North Indian equivalent to Punnagavarali, so the raga isn't assigned a performance time there either. Even if there were a corresponding North Indian raga, it would presumably be considered performable at any time of day, because in Hindustani music, ragas derived from folk music such as Pahadi or Maand are typically so considered. So Punnagavarali, being based on folk melodies, would be dubbed सर्वकालिक sarvakaalik, "at any / all times".

So there is no proscription from the standpoint of actual music theory that would prevent someone from playing Punnagavarali at night. However, in both Hindustani and Carnatic systems, some ragas accrete lore. For example, it is said that Raga Malkauns is beloved by djinns, to the extent that they'll kill you if you perform it badly. (When he explained this to me as I embarked on learning the raga, my music teacher added, "No pressure, though".)

Part of the lore of Punnagavarali is that it attracts snakes. The belief is recorded in Mario Friscia's blog, "Uncovering Sound":

Many Hindus believe that if you sing or play a song set in the snake-charming tunes, such as the punnagavarali raga, at a particular time, that is, around the dusk or at late night, you have the power to gather the snakes that live near your house.

Somewhat less grammatically, the saadhakam blog says:

There is wide belief that, if this raga is sung around the dusk or late night, may invite the attraction of snake to the place.

These blogs show that @muru is right in his comment to your question:

such music could be an invitation for snakes to come, and that's why it shouldn't be played at night.

Unless, of course, you're a Slytherin.