I am trying to do some date calculations like below:

library(optionstrat)
#compute the difference between two dates
tdiff("2022-10-20", "2022-11-30", "days") # return with an integer of 41, which is good. 
tdiff(Sys.Date()-1, "2022-11-30", "days") # return with ***41.66***

Wondering what I did wrong in the third line, and may I ask how do I make it as an integer instead? Thank you so much.

CodePudding user response：

If you supply dates as character scalars it seems to work

library(opionstrat)
tdiff(format(Sys.Date() - 1, "%Y-%m-%d"), "2022-11-30", "days")

Unfortunately, the documentation for optionstrat::tdiff is not very detailed. It seems that tdiff simply calls difftime under the hood. difftime in turn needs two time points, either as a POSIXct/Date object or as something that is coercible to a POSIXct/Date object. It seems that providing time1 and time2 in different formats (one as a Date object and one as a character scalar) does not work well.

(Tangential) PS. I don't really see the point of optionstrat::tdiff, seeing that it's really just difftime with the two time points swapped.