The phrase "at an unexpected time" is correct and usable in written English.
You can use it to describe an event or occurrence that happens suddenly or without prior notice.
Example: "The meeting was scheduled for next week, but it was called at an unexpected time, catching everyone off guard."
Alternatives: "at an unforeseen moment" or "at an unanticipated time".
BOSTON — Getting voters' attention for a special election at an unexpected time of year is hard enough.
Apart from providing a delicious crop at an unexpected time of year, autumn raspberries have the added advantage of not attracting birds for a free meal.
Regardless, this will probably be a phone interview, coming at an unexpected time and completely out-of-the-blue.
"The key to a woman's heart is an unexpected gift at an unexpected time".
On Day 3, surprise your partner with sex at an unexpected time.
Eventually, at an unexpected time, random lights around the house go on, often in the closet, where we never overcame our instinct of reaching for the switch.
Within moments, however, there was neither silence nor reverence anywhere in the building, for a power struggle, in a completely unexpected form and at a completely unexpected time, threatened to split the Coordinating Committee.
As the Rangers returned to their practice facility Tuesday to prepare for the rest of their season, which begins anew Friday night with their home opener against Chicago, they described a pull-together moment that came at a most unexpected time.
With this approach, we were able to reconstitute a time course of mRNA changes related to the cell cycle and observed a sharp peak at an unexpected early time point, namely P9.5, during which a large cluster of genes related to the cell cycle was upregulated.
Make frequent short glances at him at the most unexpected time (i.e. at recess, from one table to another).
How selfish of Apple to launch new phones at such a completely unexpected time.
