Anytime is better for investment if it is a long term investment. For short term investment, more scrupulous study is required. Thus if long term investment is in mind then dont look at current price, soon or later great returns are waiting.
Anytime and any day is how I invest in things as well. It also depends on the type of investment and of course the time length of it matters also. If the investment is just something that could be bartered later on other than for money then I would invest immediately.
Well as the price is moving towards a new ath, this seems to be the right time to invest. Today the price has crossed the ATH since 45 days. Possibly the increasing adoption is the cause for such an growth in the price. Along with the same Japan's regulated use makes a big path for the further growth of bitcoin.