Is there a way to tell when a bond will pay its coupon? I know there are bonds that pay annually and others pay twice a year, but can I know this (these) dates before actually buying the bond?
This Hyundai bond can serve as an example.
It will pay periodic coupons starting from the issue date. You can also work backwards from the maturity date. In your example the bond matures on March 6, 2022 and pays interest annually (although I find conflicting data from other sites) so it pays interest every March 6th (plus or minus a few days depending on what the prospectus says).
Note that the timing of the coupon doesn't affect the bond price, since the price you pay for a bond included any interest that accrues up to that point, so if you buy a bond the day before it pays a coupon, you're also paying for the interest that's accrued to that point, so effectively you're only getting one day's worth of interest.