diff --git a/crates/domain/src/services/ical.rs b/crates/domain/src/services/ical.rs
index 60ff60a..c7c3b7f 100644
--- a/crates/domain/src/services/ical.rs
+++ b/crates/domain/src/services/ical.rs
@@ -305,7 +305,7 @@ fn parse_duration(s: &str) -> DomainResult<u32> {
         )));
     }
     let body = &s[2..];
-    let mut total_mins: u32 = 0;
+    let mut total_secs: u32 = 0;
     let mut num_buf = String::new();
 
     for c in body.chars() {
@@ -317,9 +317,9 @@ fn parse_duration(s: &str) -> DomainResult<u32> {
             })?;
             num_buf.clear();
             match c {
-                'H' => total_mins += n * 60,
-                'M' => total_mins += n,
-                'S' => total_mins += n / 60,
+                'H' => total_secs += n * 3600,
+                'M' => total_secs += n * 60,
+                'S' => total_secs += n,
                 _ => {
                     return Err(crate::DomainError::validation(format!(
                         "unknown DURATION unit '{c}' in: {s}"
@@ -328,6 +328,7 @@ fn parse_duration(s: &str) -> DomainResult<u32> {
             }
         }
     }
+    let total_mins = (total_secs + 59) / 60;
     if total_mins == 0 {
         return Err(crate::DomainError::validation(format!(
             "zero DURATION: {s}"