[tisc]

I like to combine those:

    const RESEND_DELAY_MS = ONE_HOUR_IN_MS;

Having the unit in the name saved me more than once and having non-contextual constants for sizes increases readability imo.

[kissgyorgy]

I do this instead:

    const RESEND_DELAY_MS = 1 * 60 * 60 * 1000;  // one hour

Essentially the same, but the lack of extra variable spares one jump. Also you can change it without introducing a new variable (no dependency).