R, Format date on X axis using ggplot

Question

After aggregating, "filtering" and parsing a column with date and hours by using as.Date, also transforming it by using melt function, my data looks like this:

DATE    variable value
1 13-09-20  Billete_50 20405
2 14-09-20  Billete_50 19808
3 13-09-20 Billete_100 27787
4 14-09-20 Billete_100 20361
5 13-09-20       Total 48192
6 14-09-20       Total 40169

I want a linear graph to show the data, but it looks like this:

It's in spanish, I'm sorry, but the date is almost the same, it may say only September (Sep), but it is showing October, January, April, July, then back to October.

This is my ggplot line:

ggplot(plotCajero1Melted, aes(x=DATE, y=value, col=variable)) + geom_line() +xlab("Fecha") +ylab("Saldo") +ggtitle("Cajero 1")

What should I do? It's something with the date? I was thinking in the year, it is represented in a short way, probably it is making ggplot to have a weird behavior, or maybe a ggplot option that i'm missing?

Answer 1

You're right, your date format is not read as it should be (it seems to be read as Year-Month-Day).

You can modify the date format for example by using the function dmy from lubridate package to indicate r to read the date as Day-Month-Year:

library(lubridate)
df$DATE <- dmy(df$DATE)

ggplot(df, aes(x = DATE, y = value, color = variable))+
  geom_line()

Is it what you are looking for ?