As far as the integrated Windows Update (WU) function is concerned, Patch Tuesday begins at 10:00 a.m. Pacific Time.
The updates show up in Download Center before they are added to WU, and the KB articles are unlocked later.
There have been cases where vulnerability information became public or actual worms were circulating prior to the next scheduled Patch Tuesday.
In critical cases Microsoft issues corresponding patches as they become ready, alleviating the risk if updates are checked for and installed frequently.
These releases brought new functionalities, and are governed by Microsoft's modern lifecycle policy, which specifies a support period of 18–36 months.
This is in contrast to previous Windows versions, which received only infrequent updates via service packs, and whose support was governed by the fixed lifecycle policy.
[20] Adobe Systems' update schedule for Flash Player since November 2012 also coincides with Patch Tuesday.
"[24] Furthermore, the Windows Update servers of Microsoft do not honor the TCP's slow start congestion control strategy.
[25] As a result, other users on the same network may experience significantly slower connections from machines actively retrieving updates.
This can be particularly noticeable in environments where many machines individually retrieve updates over a shared, bandwidth-constrained link such as those found in many multi-PC homes and small to medium-sized businesses.
This can potentially distribute updates faster while reducing usage for networks with a metered connection.