sorry, I think your choice has some problems.
annual frequency=0.4 and you may make a straightforward transformation. so the daily frequency lamda=0.4/365.
and you can calculate it. given any day, the frequency of no claim is exp(-0.4/365).
and it’s just a binomial distribution, if you want to see some claims at the second half.
at the upper half year, there is a 182 days and making a simplified assumtion that there is no more one claim at any day.
it’s a combinatorial calculation. From 182 days, you chose 39 day that reported a claim and there are 143 no claim days.
the combinatorial part is infinity.