diff --git a/stdlib/Dates/src/adjusters.jl b/stdlib/Dates/src/adjusters.jl
index 4687b22badad5..d5617ba8cf93c 100644
--- a/stdlib/Dates/src/adjusters.jl
+++ b/stdlib/Dates/src/adjusters.jl
@@ -2,10 +2,12 @@
 
 ### truncation
 Base.trunc(dt::Date, p::Type{Year}) = Date(UTD(totaldays(year(dt), 1, 1)))
+Base.trunc(dt::Date, p::Type{Quarter}) = firstdayofquarter(dt)
 Base.trunc(dt::Date, p::Type{Month}) = firstdayofmonth(dt)
 Base.trunc(dt::Date, p::Type{Day}) = dt
 
 Base.trunc(dt::DateTime, p::Type{Year}) = DateTime(trunc(Date(dt), Year))
+Base.trunc(dt::DateTime, p::Type{Quarter}) = DateTime(trunc(Date(dt), Quarter))
 Base.trunc(dt::DateTime, p::Type{Month}) = DateTime(trunc(Date(dt), Month))
 Base.trunc(dt::DateTime, p::Type{Day}) = DateTime(Date(dt))
 Base.trunc(dt::DateTime, p::Type{Hour}) = dt - Minute(dt) - Second(dt) - Millisecond(dt)