Both marks are world leaders.
The schedule can be found here:
http://liveresults.co.za/
The women's 400 final was scheduled for 13:10 and the 800 final for 14:00 - so 50 minutes later.
She also had to run heats yesterday but they were 3 hours 5 minutes apart.
Here are the results.
400m heat
Heats
1 Tsholofelo Thipe 30 Anwn A 52.88Q 2
2 Zoe Engler 24 Kzna A 54.83Q 3
3 Caster Semenya 25 Acnw A 55.16Q 1
4 Rorisang Rammonye 26 Anwn A 55.28Q 3
5 Sonja Van Der Merwe 24 Wpa A 55.46Q 2
6 Armoure Le Roux 18 Cga A 55.49Q 1
7 Soandri Meyer 28 Agn A 55.61q 3
8 Jeanelle Griesel 19 Agn A 55.64q 3
9 Cindy Von Alefeldt 18 Cga 55.79 2
10 Danel Holton 22 Acnw 56.63 1
11 Janet Seeliger 21 Agn-Ind 58.35 3
12 Boitumelo Seleka 26 Anwn 58.58 1
13 Carina Swiegers 21 Acnw 59.29 2
14 Anrune Liebenberg (T47) Sasapd 59.60 3
-- Fina Dube 21 Cga DNS 2
-- Beetrice Themane 16 Cga DNS 2
-- Mametsa Sebeka 21 Atra DNS 3
-- Thakane Maphoho 18 Les X1:03.51 2
800m heat
Heats
1 Caster Semenya 25 Acnw O 2:00.46Q 1
2 Simonay Weitsz 17 Cga 2:10.32Q 2
3 Liza Kellerman 17 Cga 2:08.52Q 1
4 Fina Dube 21 Cga 2:11.16Q 2
5 Mandie Brandt 34 Bola 2:08.75Q 1
6 Beetrice Themane 16 Cga 2:11.50Q 2
7 Gena Lofstrand 21 Acnw 2:10.14q 1
8 Cindy Von Alefeldt 18 Cga 2:10.85q 1
9 Anuscha Nice 25 Agn 2:11.85 2
10 Kelly Fletcher 22 Kzna 2:11.86 2
11 Celia Stramrood 18 Cga-Ind 2:12.12 1
12 Malethabo Seema 19 Agn 2:12.78 2
13 Lushano Smith 22 Kzna 2:13.50 2
-- Thandi Sehohle 20 Cga DNF 1
-- Rorisang Rammonye 26 Anwn DNF 1
400m final
Finals
1 Caster Semenya 25 Acnw 50.74W
2 Zoe Engler 24 Kzna 53.30A
3 Tsholofelo Thipe 30 Anwn 54.11A
4 Rorisang Rammonye 26 Anwn 54.45A
5 Jeanelle Griesel 19 Agn 54.59A
6 Sonja Van Der Merwe 24 Wpa 55.04A
7 Soandri Meyer 28 Agn 55.35A
8 Armoure Le Roux 18 Cga 55.38A
800 final
Finals
1 Caster Semenya 25 Acnw 1:58.45W
2 Liza Kellerman 17 Cga 2:05.75A
3 Gena Lofstrand 21 Acnw 2:06.65
4 Mandie Brandt 34 Bola 2:07.16
5 Fina Dube 21 Cga 2:08.90
6 Simonay Weitsz 17 Cga 2:09.89
7 Cindy Von Alefeldt 18 Cga 2:12.44
8 Beetrice Themane 16 Cga 2:15.48