I have checked to make sure I didn't have any system apps greenified or frozen and done several reboots after adjusting time zones and playing around with manual and auto time/timezones settings.
I cleared the clock app's cache and app data which did something (see image below) but I can't make any sense of it. Seems to me that some coding has been altered in some way but I don't recall messing with anything involving system time or alarms. I'm also not quite sure when this started as last night was the first time I have set my alarm since I have had the phone for about 4 months.
Setting more than an hour.
Less than the hour.
If set for one minute after current time snooze notification pops up.
After clearing clock cache and data.
Sent from my Nexus 5 using Tapatalk