Вы можете попробовать код ниже
df <- `rownames<-`(within(df,Date <- format(as.Date("20-01-22","%y-%m-%d")+Date,"%y-%m-%d")),NULL)
так, чтобы
> df
Provice Lat Long Date Recovered
1 Anhui 31.82570 117.2264 20-01-22 0
2 Chongqing 30.05720 107.8740 20-01-22 0
3 Guangdong 23.34170 113.4244 20-01-22 0
4 Henan 33.88202 113.6140 20-01-22 0
5 Hubei 30.97560 112.2707 20-01-22 28
6 Hunan 27.61040 111.7088 20-01-22 0
7 Jiangsu 32.97110 119.4550 20-01-22 0
8 Jiangxi 27.61400 115.7221 20-01-22 0
9 Shandong 36.34270 118.1498 20-01-22 0
10 Zhejiang 29.18320 120.0934 20-01-22 0
11 Anhui 31.82570 117.2264 20-01-23 0
12 Chongqing 30.05720 107.8740 20-01-23 0
13 Guangdong 23.34170 113.4244 20-01-23 2
14 Henan 33.88202 113.6140 20-01-23 0
15 Hubei 30.97560 112.2707 20-01-23 28
16 Hunan 27.61040 111.7088 20-01-23 0
17 Jiangsu 32.97110 119.4550 20-01-23 0
18 Jiangxi 27.61400 115.7221 20-01-23 0
19 Shandong 36.34270 118.1498 20-01-23 0
20 Zhejiang 29.18320 120.0934 20-01-23 0
ДАННЫЕ
df <- structure(list(Provice = c("Anhui", "Chongqing", "Guangdong",
"Henan", "Hubei", "Hunan", "Jiangsu", "Jiangxi", "Shandong",
"Zhejiang", "Anhui", "Chongqing", "Guangdong", "Henan", "Hubei",
"Hunan", "Jiangsu", "Jiangxi", "Shandong", "Zhejiang"), Lat = c(31.8257,
30.0572, 23.3417, 33.88202, 30.9756, 27.6104, 32.9711, 27.614,
36.3427, 29.1832, 31.8257, 30.0572, 23.3417, 33.88202, 30.9756,
27.6104, 32.9711, 27.614, 36.3427, 29.1832), Long = c(117.2264,
107.874, 113.4244, 113.614, 112.2707, 111.7088, 119.455, 115.7221,
118.1498, 120.0934, 117.2264, 107.874, 113.4244, 113.614, 112.2707,
111.7088, 119.455, 115.7221, 118.1498, 120.0934), Date = c(1L,
1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 2L,
2L, 2L, 2L), Recovered = c(0L, 0L, 0L, 0L, 28L, 0L, 0L, 0L, 0L,
0L, 0L, 0L, 2L, 0L, 28L, 0L, 0L, 0L, 0L, 0L)), class = "data.frame", row.names = c("Anhui.1",
"Chongqing.1", "Guangdong.1", "Henan.1", "Hubei.1", "Hunan.1",
"Jiangsu.1", "Jiangxi.1", "Shandong.1", "Zhejiang.1", "Anhui.2",
"Chongqing.2", "Guangdong.2", "Henan.2", "Hubei.2", "Hunan.2",
"Jiangsu.2", "Jiangxi.2", "Shandong.2", "Zhejiang.2"))