X-Git-Url: http://wien.tomnetworks.com/gitweb/?a=blobdiff_plain;f=mcs%2Fclass%2Fcorlib%2FSystem%2FTimeZoneInfo.cs;h=0c17412242c835af7107d559a158ce9be1e25444;hb=a27db5252facf504e7995e6abe41ab5f1d3ec506;hp=a61f048476015f52cae0657687f4ca9eb62f3d6f;hpb=11dd7619659f5dfdb8b94d6cde50cf8f078d7476;p=mono.git

diff --git a/mcs/class/corlib/System/TimeZoneInfo.cs b/mcs/class/corlib/System/TimeZoneInfo.cs
index a61f0484760..0c17412242c 100644
--- a/mcs/class/corlib/System/TimeZoneInfo.cs
+++ b/mcs/class/corlib/System/TimeZoneInfo.cs
@@ -1295,8 +1295,12 @@ namespace System
 				} else {
 					if (daylightDisplayName != ttype.Name)
 						daylightDisplayName = ttype.Name;
-					if (dstDelta.TotalSeconds != ttype.Offset - baseUtcOffset.TotalSeconds)
-						dstDelta = new TimeSpan(0, 0, ttype.Offset) - baseUtcOffset;
+					if (dstDelta.TotalSeconds != ttype.Offset - baseUtcOffset.TotalSeconds) {
+						// Round to nearest minute, since it's not possible to create an adjustment rule
+						// with sub-minute precision ("The TimeSpan parameter cannot be specified more precisely than whole minutes.")
+						// This happens with Europe/Dublin, which had an offset of 34 minutes and 39 seconds in 1916.
+						dstDelta = new TimeSpan (0, 0, ttype.Offset - ttype.Offset % 60) - baseUtcOffset;
+					}
 
 					dst_start = ttime;
 					dst_observed = true;