[Quantlib-dev] Ex-coupon adjustment based on unadjusted coupon dates

[Francois B. <ig...@gm...>]

Hi all,

In South Africa, bond settlement is T+3 trading days and the ex-coupon
period is 10 calendar days from the UNadjusted coupon payment date.

So for a trade date of 2017-06-30 the settlement date is 2017-07-05 (over a
weekend).

One specific bond, the R207, has a coupon payable on 2017-07-15 (a
Saturday), which is adjusted to Monday (BDC = Following).

The correct ex-coupon date should be 2017-07-15 - 10 calendar days =
2017-07-05, which means on the trade date of 2017-06-30 that coupon was
already ex.

However, I see in fixedratecoupon.cpp, line 154+ that the ex-coupon date is
calculated based on the adjusted coupon payment date (line 166).

Unless there is a better alternative, I'd like to add a parameter to the
ex-coupon details to enable the calculation of the ex-coupon date based on
the UNadjusted coupon payment date. If you are happy with this, I'll submit
a PR, but I just wanted to confirm with you first.

thanks
Francois Botha