Bugzilla

The `testWeeklyNOccurrences` tests didn't fail during the try run but did [fail after landing](https://treeherder.mozilla.org/#/jobs?repo=comm-central&group_state=expanded&selectedJob=254332485&revision=9d7a0c93a3b1aaf72df2acabe83215fcf82fe0ab&searchStr=osx%2Cmozmill).  This patch fixes them.  

The changes are the same as those for the other tests that were failing on macOS.  So I'd say we can safely forego review of this patch since the previous changes that were similar were reviewed (r=philipp).

Here's the try run shows that this patch fixed those tests (assuming we're not getting more false successes):
https://treeherder.mozilla.org/#/jobs?repo=try-comm-central&revision=0841805de49499000dea91ceecad404921c6e5dc

The `testWeeklyNOccurrences` tests didn't fail during the try run but did [fail after landing](https://treeherder.mozilla.org/#/jobs?repo=comm-central&group_state=expanded&selectedJob=254332485&revision=9d7a0c93a3b1aaf72df2acabe83215fcf82fe0ab&searchStr=osx%2Cmozmill).  This patch fixes them.  

The changes are the same as those for the other tests that were failing on macOS.  So I'd say we can safely forego review of this patch since the previous changes that were similar were reviewed (r=philipp).

Here's the try run that shows that this patch fixed those tests (assuming we're not getting more false successes):
https://treeherder.mozilla.org/#/jobs?repo=try-comm-central&revision=0841805de49499000dea91ceecad404921c6e5dc

Mysteriously, the `testWeeklyNOccurrences` tests didn't fail during the try run but did [fail after landing](https://treeherder.mozilla.org/#/jobs?repo=comm-central&group_state=expanded&selectedJob=254332485&revision=9d7a0c93a3b1aaf72df2acabe83215fcf82fe0ab&searchStr=osx%2Cmozmill).  This patch fixes them.  

The changes are the same as those for the other tests that were failing on macOS.  So I'd say we can safely forego review of this patch since the previous changes that were similar were reviewed (r=philipp).

Here's the try run that shows that this patch fixed those tests (assuming we're not getting more false successes):
https://treeherder.mozilla.org/#/jobs?repo=try-comm-central&revision=0841805de49499000dea91ceecad404921c6e5dc